1.
Chemical formula
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These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulas can fully specify the structure of only the simplest of molecules and chemical substances, the simplest types of chemical formulas are called empirical formulas, which use letters and numbers indicating the numerical proportions of atoms of each type. Molecular formulas indicate the numbers of each type of atom in a molecule. For example, the formula for glucose is CH2O, while its molecular formula is C6H12O6. This is possible if the relevant bonding is easy to show in one dimension, an example is the condensed molecular/chemical formula for ethanol, which is CH3-CH2-OH or CH3CH2OH. For reasons of structural complexity, there is no condensed chemical formula that specifies glucose, chemical formulas may be used in chemical equations to describe chemical reactions and other chemical transformations, such as the dissolving of ionic compounds into solution. A chemical formula identifies each constituent element by its chemical symbol, in empirical formulas, these proportions begin with a key element and then assign numbers of atoms of the other elements in the compound, as ratios to the key element. For molecular compounds, these numbers can all be expressed as whole numbers. For example, the formula of ethanol may be written C2H6O because the molecules of ethanol all contain two carbon atoms, six hydrogen atoms, and one oxygen atom. Some types of compounds, however, cannot be written with entirely whole-number empirical formulas. An example is boron carbide, whose formula of CBn is a variable non-whole number ratio with n ranging from over 4 to more than 6.5. When the chemical compound of the consists of simple molecules. These types of formulas are known as molecular formulas and condensed formulas. A molecular formula enumerates the number of atoms to reflect those in the molecule, so that the formula for glucose is C6H12O6 rather than the glucose empirical formula. However, except for very simple substances, molecular chemical formulas lack needed structural information, for simple molecules, a condensed formula is a type of chemical formula that may fully imply a correct structural formula. For example, ethanol may be represented by the chemical formula CH3CH2OH
2.
Crystal system
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In crystallography, the terms crystal system, crystal family and lattice system each refer to one of several classes of space groups, lattices, point groups or crystals. Informally, two crystals are in the crystal system if they have similar symmetries, though there are many exceptions to this. Space groups and crystals are divided into seven crystal systems according to their point groups, five of the crystal systems are essentially the same as five of the lattice systems, but the hexagonal and trigonal crystal systems differ from the hexagonal and rhombohedral lattice systems. The six crystal families are formed by combining the hexagonal and trigonal crystal systems into one hexagonal family, a lattice system is a class of lattices with the same set of lattice point groups, which are subgroups of the arithmetic crystal classes. The 14 Bravais lattices are grouped into seven lattice systems, triclinic, monoclinic, orthorhombic, tetragonal, rhombohedral, hexagonal, in a crystal system, a set of point groups and their corresponding space groups are assigned to a lattice system. Of the 32 point groups that exist in three dimensions, most are assigned to only one system, in which case both the crystal and lattice systems have the same name. However, five point groups are assigned to two systems, rhombohedral and hexagonal, because both exhibit threefold rotational symmetry. These point groups are assigned to the crystal system. In total there are seven crystal systems, triclinic, monoclinic, orthorhombic, tetragonal, trigonal, hexagonal, a crystal family is determined by lattices and point groups. It is formed by combining crystal systems which have space groups assigned to a lattice system. In three dimensions, the families and systems are identical, except the hexagonal and trigonal crystal systems. In total there are six families, triclinic, monoclinic, orthorhombic, tetragonal, hexagonal. Spaces with less than three dimensions have the number of crystal systems, crystal families and lattice systems. In one-dimensional space, there is one crystal system, in 2D space, there are four crystal systems, oblique, rectangular, square and hexagonal. The relation between three-dimensional crystal families, crystal systems and lattice systems is shown in the table, Note. To avoid confusion of terminology, the term trigonal lattice is not used, if the original structure and inverted structure are identical, then the structure is centrosymmetric. Still, even for non-centrosymmetric case, inverted structure in some cases can be rotated to align with the original structure and this is the case of non-centrosymmetric achiral structure. If the inverted structure cannot be rotated to align with the structure, then the structure is chiral
3.
Orthorhombic crystal system
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In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. All three bases intersect at 90° angles, so the three lattice vectors remain mutually orthogonal, there are two orthorhombic Bravais lattices in two dimensions, Primitive rectangular and centered rectangular. The primitive rectangular lattice can also be described by a centered rhombic unit cell, there are four orthorhombic Bravais lattices, primitive orthorhombic, base-centered orthorhombic, body-centered orthorhombic, and face-centered orthorhombic. In this axis setting, the primitive and base-centered lattices interchange in centering type, crystal structure Overview of all space groups Hurlbut, Cornelius S. Klein, Cornelis. Hahn, Theo, ed. International Tables for Crystallography, Volume A, Space Group Symmetry
4.
Crystallographic point group
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For a periodic crystal, the group must also be consistent with maintenance of the three-dimensional translational symmetry that defines crystallinity. The macroscopic properties of a crystal would look exactly the same before, in the classification of crystals, each point group is also known as a crystal class. There are infinitely many three-dimensional point groups, however, the crystallographic restriction of the infinite families of general point groups results in there being only 32 crystallographic point groups. These 32 point groups are one-and-the same as the 32 types of morphological crystalline symmetries derived in 1830 by Johann Friedrich Christian Hessel from a consideration of observed crystal forms, the point groups are denoted by their component symmetries. There are a few standard notations used by crystallographers, mineralogists, for the correspondence of the two systems below, see crystal system. In Schoenflies notation, point groups are denoted by a symbol with a subscript. The symbols used in crystallography mean the following, Cn indicates that the group has a rotation axis. Cnh is Cn with the addition of a plane perpendicular to the axis of rotation. Cnv is Cn with the addition of n mirror planes parallel to the axis of rotation, s2n denotes a group that contains only a 2n-fold rotation-reflection axis. Dn indicates that the group has a rotation axis plus n twofold axes perpendicular to that axis. Dnh has, in addition, a plane perpendicular to the n-fold axis. Dnd has, in addition to the elements of Dn, mirror planes parallel to the n-fold axis, the letter T indicates that the group has the symmetry of a tetrahedron. Td includes improper rotation operations, T excludes improper rotation operations, the letter O indicates that the group has the symmetry of an octahedron, with or without improper operations. Due to the crystallographic restriction theorem, n =1,2,3,4, d4d and D6d are actually forbidden because they contain improper rotations with n=8 and 12 respectively. The 27 point groups in the table plus T, Td, Th, O, an abbreviated form of the Hermann–Mauguin notation commonly used for space groups also serves to describe crystallographic point groups. Group names are Molecular symmetry Point group Space group Point groups in three dimensions Crystal system Point-group symbols in International Tables for Crystallography,12.1, pp. 818-820 Names and symbols of the 32 crystal classes in International Tables for Crystallography. 10.1, p.794 Pictorial overview of the 32 groups Point Groups - Flow Chart Inorganic Chemistry Group Theory Practice Problems
5.
H-M symbol
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In geometry, Hermann–Mauguin notation is used to represent the symmetry elements in point groups, plane groups and space groups. It is named after the German crystallographer Carl Hermann and the French mineralogist Charles-Victor Mauguin and this notation is sometimes called international notation, because it was adopted as standard by the International Tables For Crystallography since their first edition in 1935. Rotation axes are denoted by a number n —1,2,3,4,5,6,7,8, for improper rotations, Hermann–Mauguin symbols show rotoinversion axes, unlike Schoenflies and Shubnikov notations, where the preference is given to rotation-reflection axes. The rotoinversion axes are represented by the number with a macron. The symbol for a plane is m. The direction of the plane is defined as the direction of perpendicular to the face. Hermann–Mauguin symbols show symmetrically non-equivalent axes and planes, the direction of a symmetry element is represented by its position in the Hermann–Mauguin symbol. If a rotation axis n and a mirror plane m have the same direction, if two or more axes have the same direction, the axis with higher symmetry is shown. Higher symmetry means that the axis generates a pattern with more points, for example, rotation axes 3,4,5,6,7,8 generate 3-, 4-, 5-, 6-, 7-, 8-point patterns, respectively. Improper rotation axes 3,4,5,6,7,8 generate 6-, 4-, 10-, 6-, 14-, 8-point patterns, if both, the rotation and rotoinversion axes satisfy the previous rule, the rotation axis should be chosen. For example, 3/m combination is equivalent to 6, since 6 generates 6 points, and 3 generates only 3,6 should be written instead of 3/m. Analogously, in the case when both 3 and 3 axes are present,3 should be written, however we write 4/m, not 4/m, because both 4 and 4 generate four points. Finally, the Hermann–Mauguin symbol depends on the type of the group and these groups may contain only two-fold axes, mirror planes, and inversion center. These are the point groups 1 and 1,2, m, and 2/m, and 222, 2/m2/m2/m. If the symbol contains three positions, then they denote symmetry elements in the x, y, z direction, First position — primary direction — z direction, assigned to the higher-order axis. Second position — symmetrically equivalent secondary directions, which are perpendicular to the z-axis and these can be 2, m, or 2/m. Third position — symmetrically equivalent tertiary directions, passing between secondary directions and these can be 2, m, or 2/m. These are the crystallographic groups 3,32, 3m,3, and 32/m,4,422, 4mm,4, 42m, 4/m, and 4/m2/m2/m, and 6,622, 6mm,6, 6m2, 6/m, and 6/m2/m2/m
6.
Space group
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In mathematics, physics and chemistry, a space group is the symmetry group of a configuration in space, usually in three dimensions. In three dimensions, there are 219 distinct types, or 230 if chiral copies are considered distinct, Space groups are also studied in dimensions other than 3 where they are sometimes called Bieberbach groups, and are discrete cocompact groups of isometries of an oriented Euclidean space. In crystallography, space groups are called the crystallographic or Fedorov groups. A definitive source regarding 3-dimensional space groups is the International Tables for Crystallography, in 1879 Leonhard Sohncke listed the 65 space groups whose elements preserve the orientation. More accurately, he listed 66 groups, but Fedorov and Schönflies both noticed that two of them were really the same, the space groups in 3 dimensions were first enumerated by Fedorov, and shortly afterwards were independently enumerated by Schönflies. The correct list of 230 space groups was found by 1892 during correspondence between Fedorov and Schönflies, burckhardt describes the history of the discovery of the space groups in detail. The space groups in three dimensions are made from combinations of the 32 crystallographic point groups with the 14 Bravais lattices, the combination of all these symmetry operations results in a total of 230 different space groups describing all possible crystal symmetries. The elements of the space group fixing a point of space are rotations, reflections, the identity element, the translations form a normal abelian subgroup of rank 3, called the Bravais lattice. There are 14 possible types of Bravais lattice, the quotient of the space group by the Bravais lattice is a finite group which is one of the 32 possible point groups. Translation is defined as the moves from one point to another point. A glide plane is a reflection in a plane, followed by a parallel with that plane. This is noted by a, b or c, depending on which axis the glide is along. There is also the n glide, which is a glide along the half of a diagonal of a face, and the d glide, the latter is called the diamond glide plane as it features in the diamond structure. In 17 space groups, due to the centering of the cell, the glides occur in two directions simultaneously, i. e. the same glide plane can be called b or c, a or b. For example, group Abm2 could be also called Acm2, group Ccca could be called Cccb, in 1992, it was suggested to use symbol e for such planes. The symbols for five groups have been modified, A screw axis is a rotation about an axis. These are noted by a number, n, to describe the degree of rotation, the degree of translation is then added as a subscript showing how far along the axis the translation is, as a portion of the parallel lattice vector. So,21 is a rotation followed by a translation of 1/2 of the lattice vector
7.
Crystal structure
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In crystallography, crystal structure is a description of the ordered arrangement of atoms, ions or molecules in a crystalline material. Ordered structures occur from the nature of the constituent particles to form symmetric patterns that repeat along the principal directions of three-dimensional space in matter. The smallest group of particles in the material that constitutes the pattern is the unit cell of the structure. The unit cell completely defines the symmetry and structure of the crystal lattice. The repeating patterns are said to be located at the points of the Bravais lattice, the lengths of the principal axes, or edges, of the unit cell and the angles between them are the lattice constants, also called lattice parameters. The symmetry properties of the crystal are described by the concept of space groups, all possible symmetric arrangements of particles in three-dimensional space may be described by the 230 space groups. The crystal structure and symmetry play a role in determining many physical properties, such as cleavage, electronic band structure. The crystal structure of a material can be described in terms of its unit cell, the unit cell is a box containing one or more atoms arranged in three dimensions. The unit cells stacked in three-dimensional space describe the arrangement of atoms of the crystal. Commonly, atomic positions are represented in terms of fractional coordinates, the atom positions within the unit cell can be calculated through application of symmetry operations to the asymmetric unit. The asymmetric unit refers to the smallest possible occupation of space within the unit cell and this does not, however imply that the entirety of the asymmetric unit must lie within the boundaries of the unit cell. Symmetric transformations of atom positions are calculated from the group of the crystal structure. Vectors and planes in a lattice are described by the three-value Miller index notation. It uses the indices ℓ, m, and n as directional parameters, which are separated by 90°, by definition, the syntax denotes a plane that intercepts the three points a1/ℓ, a2/m, and a3/n, or some multiple thereof. That is, the Miller indices are proportional to the inverses of the intercepts of the plane with the unit cell, if one or more of the indices is zero, it means that the planes do not intersect that axis. A plane containing a coordinate axis is translated so that it no longer contains that axis before its Miller indices are determined, the Miller indices for a plane are integers with no common factors. Negative indices are indicated with horizontal bars, as in, in an orthogonal coordinate system for a cubic cell, the Miller indices of a plane are the Cartesian components of a vector normal to the plane. Likewise, the planes are geometric planes linking nodes
8.
Mohs scale of mineral hardness
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The Mohs scale of mineral hardness is a qualitative ordinal scale characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. Created in 1812 by German geologist and mineralogist Friedrich Mohs, it is one of several definitions of hardness in materials science, while greatly facilitating the identification of minerals in the field, the Mohs scale does not show how well hard materials perform in an industrial setting. Despite its lack of precision, the Mohs scale is highly relevant for field geologists, the Mohs scale hardness of minerals can be commonly found in reference sheets. Reference materials may be expected to have a uniform Mohs hardness, the Mohs scale of mineral hardness is based on the ability of one natural sample of mineral to scratch another mineral visibly. The samples of matter used by Mohs are all different minerals, Minerals are pure substances found in nature. Rocks are made up of one or more minerals, as the hardest known naturally occurring substance when the scale was designed, diamonds are at the top of the scale. The hardness of a material is measured against the scale by finding the hardest material that the material can scratch. For example, if material is scratched by apatite but not by fluorite. Scratching a material for the purposes of the Mohs scale means creating non-elastic dislocations visible to the naked eye, frequently, materials that are lower on the Mohs scale can create microscopic, non-elastic dislocations on materials that have a higher Mohs number. The Mohs scale is an ordinal scale. For example, corundum is twice as hard as topaz, the table below shows the comparison with the absolute hardness measured by a sclerometer, with pictorial examples. On the Mohs scale, a streak plate has a hardness of 7.0, using these ordinary materials of known hardness can be a simple way to approximate the position of a mineral on the scale. The table below incorporates additional substances that may fall between levels, Comparison between Hardness and Hardness, Mohs hardness of elements is taken from G. V, samsonov in Handbook of the physicochemical properties of the elements, IFI-Plenum, New York, USA,1968. The Hardness of Minerals and Rocks
9.
Lustre (mineralogy)
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Lustre or luster is the way light interacts with the surface of a crystal, rock, or mineral. The word traces its origins back to the latin lux, meaning light, a range of terms are used to describe lustre, such as earthy, metallic, greasy, and silky. Similarly, the term refers to a glassy lustre. A list of terms is given below. Lustre varies over a continuum, and so there are no rigid boundaries between the different types of lustre. The terms are frequently combined to describe types of lustre. Some minerals exhibit unusual optical phenomena, such as asterism or chatoyancy, a list of such phenomena is given below. Adamantine minerals possess a superlative lustre, which is most notably seen in diamond, such minerals are transparent or translucent, and have a high refractive index. Minerals with an adamantine lustre are uncommon, with examples being cerussite. Minerals with a degree of lustre are referred to as subadamantine, with some examples being garnet. Dull minerals exhibit little to no lustre, due to coarse granulations which scatter light in all directions, a distinction is sometimes drawn between dull minerals and earthy minerals, with the latter being coarser, and having even less lustre. Greasy minerals resemble fat or grease, a greasy lustre often occurs in minerals containing a great abundance of microscopic inclusions, with examples including opal and cordierite. Many minerals with a greasy lustre also feel greasy to the touch, metallic minerals have the lustre of polished metal, and with ideal surfaces will work as a reflective surface. Examples include galena, pyrite and magnetite, pearly minerals consist of thin transparent co-planar sheets. Light reflecting from these layers give them a lustre reminiscent of pearls, such minerals possess perfect cleavage, with examples including muscovite and stilbite. Resinous minerals have the appearance of resin, chewing gum or plastic, a principal example is amber, which is a form of fossilized resin. Silky minerals have an arrangement of extremely fine fibres, giving them a lustre reminiscent of silk. Examples include asbestos, ulexite and the satin spar variety of gypsum, a fibrous lustre is similar, but has a coarser texture
10.
Specific gravity
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This page is about the measurement using water as a reference. For a general use of gravity, see relative density. See intensive property for the property implied by specific, Apparent specific gravity is the ratio of the weight of a volume of the substance to the weight of an equal volume of the reference substance. The reference substance is always water at its densest for liquids. Nonetheless, the temperature and pressure must be specified for both the sample and the reference, pressure is nearly always 1 atm. Temperatures for both sample and reference vary from industry to industry, in British beer brewing, the practice for specific gravity as specified above is to multiply it by 1000. Being a ratio of densities, specific gravity is a dimensionless quantity, Specific gravity varies with temperature and pressure, reference and sample must be compared at the same temperature and pressure or be corrected to a standard reference temperature and pressure. Substances with a gravity of 1 are neutrally buoyant in water. Those with SG greater than 1 are denser than water and will, disregarding surface tension effects and those with an SG less than 1 are less dense than water and will float on it. In scientific work, the relationship of mass to volume is expressed directly in terms of the density of the substance under study. It is in industry where specific gravity finds wide application, often for historical reasons. True specific gravity can be expressed mathematically as, S G true = ρ sample ρ H2 O where ρ sample is the density of the sample, the density of water varies with temperature and pressure as does the density of the sample. So it is necessary to specify the temperatures and pressures at which the densities or weights were determined and it is nearly always the case that measurements are made at 1 nominal atmosphere. For true specific gravity calculations, air pressure must be considered, temperatures are specified by the notation with T s representing the temperature at which the samples density was determined and T r the temperature at which the reference density is specified. For example, SG would be understood to mean that the density of the sample was determined at 20°C and of the water at 4°C. Taking into account different sample and reference temperatures, we note that, while S G H2 O =1.000000, it is also the case that S G H2 O =0.998203 /0.999840 =0.998363. Here, temperature is being specified using the current ITS-90 scale, on the previous IPTS-68 scale, the densities at 20 °C and 4 °C are 0.9982071 and 0.9999720 respectively, resulting in an SG value for water of 0.9982343. For example, in the industry, the Plato table lists sucrose concentration by weight against true SG
11.
Mineral
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A mineral is a naturally occurring chemical compound, usually of crystalline form and abiogenic in origin. A mineral has one specific chemical composition, whereas a rock can be an aggregate of different minerals or mineraloids, the study of minerals is called mineralogy. There are over 5,300 known mineral species, over 5,070 of these have been approved by the International Mineralogical Association, the silicate minerals compose over 90% of the Earths crust. The diversity and abundance of species is controlled by the Earths chemistry. Silicon and oxygen constitute approximately 75% of the Earths crust, which translates directly into the predominance of silicate minerals, minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various species, changes in the temperature, pressure, or bulk composition of a rock mass cause changes in its minerals. Minerals can be described by their various properties, which are related to their chemical structure. Common distinguishing characteristics include crystal structure and habit, hardness, lustre, diaphaneity, colour, streak, tenacity, cleavage, fracture, parting, more specific tests for describing minerals include magnetism, taste or smell, radioactivity and reaction to acid. Minerals are classified by key chemical constituents, the two dominant systems are the Dana classification and the Strunz classification, the silicate class of minerals is subdivided into six subclasses by the degree of polymerization in the chemical structure. All silicate minerals have a unit of a 4− silica tetrahedron—that is, a silicon cation coordinated by four oxygen anions. These tetrahedra can be polymerized to give the subclasses, orthosilicates, disilicates, cyclosilicates, inosilicates, phyllosilicates, other important mineral groups include the native elements, sulfides, oxides, halides, carbonates, sulfates, and phosphates. The first criterion means that a mineral has to form by a natural process, stability at room temperature, in the simplest sense, is synonymous to the mineral being solid. More specifically, a compound has to be stable or metastable at 25 °C, modern advances have included extensive study of liquid crystals, which also extensively involve mineralogy. Minerals are chemical compounds, and as such they can be described by fixed or a variable formula, many mineral groups and species are composed of a solid solution, pure substances are not usually found because of contamination or chemical substitution. Finally, the requirement of an ordered atomic arrangement is usually synonymous with crystallinity, however, crystals are also periodic, an ordered atomic arrangement gives rise to a variety of macroscopic physical properties, such as crystal form, hardness, and cleavage. There have been recent proposals to amend the definition to consider biogenic or amorphous substances as minerals. The formal definition of an approved by the IMA in 1995, A mineral is an element or chemical compound that is normally crystalline. However, if geological processes were involved in the genesis of the compound, Mineral classification schemes and their definitions are evolving to match recent advances in mineral science
12.
Tranquility Base
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Tranquility Base is the site on the Moon where, in 1969, humans landed and walked on another celestial body for the first time. On July 20,1969, Apollo 11 crewmembers Neil Armstrong and Buzz Aldrin landed their Apollo Lunar Module Eagle at approximately 20,17,40 UTC.5 pounds of dirt and they lifted off the surface on July 21 at 17,54 UTC. Tranquility Base has remained unvisited since then. S, for more than two years, NASA planners considered a collection of 30 potential sites for the first manned landing. Site number 2, centered at 0°42′50″N 23°42′28″E, was the Sea of Tranquility site ultimately chosen, since a precision landing was not expected on the first mission, the target area was an ellipse measuring 11.5 miles east-west by 3.0 miles north-south. Thus the landing was still within the target ellipse, Armstrong named the site at 20,17,58 UTC, approximately 18 seconds after his and Aldrins successful landing, as he announced, Houston, Tranquility Base here. During training, Armstrong and Aldrin had exclusively used the callsign Eagle in simulated ground conversations, Armstrong and Aldrin decided on using Tranquility Base just before the flight, telling only Capsule Communicator Charles Duke before the mission, so Duke would not be taken by surprise. The name has become a permanent designation for the site, unlike most names given to lunar landmarks by Apollo astronauts, the International Astronomical Union officially recognizes the designation Tranquility Base. It is listed on maps as Statio Tranquillitatis, conforming to the standard use of Latin names for lunar place names. About 100 man-made objects and footprints left by Armstrong and Aldrin remain at Tranquility Base, the descent stage of the Lunar Module remains at the original point of landing. According to Aldrin, the US flag planted at the site during their moonwalk was blown over by the ascent rocket exhaust, a laser reflector was placed at the site to allow precise ongoing measurements of the distance to the Moon from Earth. A solar-powered seismometer was also left to measure moonquakes, but this stopped functioning after 21 days, various gear that was no longer needed for the return phase of the mission – including Aldrins boots – was left behind to lighten the craft for return to lunar orbit. As the site of the first human landing on a body, Tranquility Base has cultural. The U. S. states of California and New Mexico have listed it on their heritage registers, since their laws require only that listed sites have some association with the state. Despite the location of Mission Control in Houston, Texas has not granted similar status to the site, one team, led by Astrobotic Technology, announced it would attempt to land a craft at Tranquility Base
13.
Moon
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The Moon is an astronomical body that orbits planet Earth, being Earths only permanent natural satellite. It is the fifth-largest natural satellite in the Solar System, following Jupiters satellite Io, the Moon is second-densest satellite among those whose densities are known. The average distance of the Moon from the Earth is 384,400 km, the Moon is thought to have formed about 4.51 billion years ago, not long after Earth. It is the second-brightest regularly visible celestial object in Earths sky, after the Sun and its surface is actually dark, although compared to the night sky it appears very bright, with a reflectance just slightly higher than that of worn asphalt. Its prominence in the sky and its cycle of phases have made the Moon an important cultural influence since ancient times on language, calendars, art. The Moons gravitational influence produces the ocean tides, body tides, and this matching of apparent visual size will not continue in the far future. The Moons linear distance from Earth is currently increasing at a rate of 3.82 ±0.07 centimetres per year, since the Apollo 17 mission in 1972, the Moon has been visited only by uncrewed spacecraft. The usual English proper name for Earths natural satellite is the Moon, the noun moon is derived from moone, which developed from mone, which is derived from Old English mōna, which ultimately stems from Proto-Germanic *mǣnōn, like all Germanic language cognates. Occasionally, the name Luna is used, in literature, especially science fiction, Luna is used to distinguish it from other moons, while in poetry, the name has been used to denote personification of our moon. The principal modern English adjective pertaining to the Moon is lunar, a less common adjective is selenic, derived from the Ancient Greek Selene, from which is derived the prefix seleno-. Both the Greek Selene and the Roman goddess Diana were alternatively called Cynthia, the names Luna, Cynthia, and Selene are reflected in terminology for lunar orbits in words such as apolune, pericynthion, and selenocentric. The name Diana is connected to dies meaning day, several mechanisms have been proposed for the Moons formation 4.51 billion years ago, and some 60 million years after the origin of the Solar System. These hypotheses also cannot account for the angular momentum of the Earth–Moon system. This hypothesis, although not perfect, perhaps best explains the evidence, eighteen months prior to an October 1984 conference on lunar origins, Bill Hartmann, Roger Phillips, and Jeff Taylor challenged fellow lunar scientists, You have eighteen months. Go back to your Apollo data, go back to computer, do whatever you have to. Dont come to our conference unless you have something to say about the Moons birth, at the 1984 conference at Kona, Hawaii, the giant impact hypothesis emerged as the most popular. Afterward there were only two groups, the giant impact camp and the agnostics. Giant impacts are thought to have been common in the early Solar System, computer simulations of a giant impact have produced results that are consistent with the mass of the lunar core and the present angular momentum of the Earth–Moon system
14.
Neil Armstrong
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Neil Alden Armstrong was an American astronaut and the first person to walk on the Moon. He was also an engineer, naval aviator, test pilot. Before becoming an astronaut, Armstrong was an officer in the U. S. Navy and he later completed graduate studies at the University of Southern California. A participant in the U. S. Air Forces Man in Space Soonest and X-20 Dyna-Soar human spaceflight programs and he made his first space flight as command pilot of Gemini 8 in March 1966, becoming NASAs first civilian astronaut to fly in space. He performed the first docking of two spacecraft, with pilot David Scott and this mission was aborted after Armstrong used some of his reentry control fuel to prevent a dangerous spin caused by a stuck thruster, in the first in-flight space emergency. Armstrongs second and last spaceflight was as commander of Apollo 11, along with Collins and Aldrin, Armstrong was awarded the Presidential Medal of Freedom by President Richard Nixon. President Jimmy Carter presented Armstrong the Congressional Space Medal of Honor in 1978, Armstrong and his former crewmates received the Congressional Gold Medal in 2009. Armstrong died in Cincinnati, Ohio on August 25,2012, at the age of 82, Armstrong was born on August 5,1930 near Wapakoneta, Ohio, the son of Stephen Koenig Armstrong and Viola Louise Engel. He was of German, Irish, and Scottish ancestry, and had a sister, June. His father worked as an auditor for the Ohio state government, Armstrongs love for flying grew during this time, having gotten off to an early start when his father took his two-year-old son to the Cleveland Air Races. When he was five, he experienced his first airplane flight in Warren, Ohio on July 20,1936 when he and his father took a ride in a Ford Trimotor and his fathers last move was in 1944, back to Wapakoneta. Armstrong attended Blume High School and took flying lessons at the grassy Wapakoneta airfield and he earned a student flight certificate on his 16th birthday, then soloed later in August, all before he had a drivers license. Armstrong was active in the Boy Scouts and earned the rank of Eagle Scout, as an adult, he was recognized by the Boy Scouts of America with its Distinguished Eagle Scout Award and Silver Buffalo Award. Houston replied, Thank you, Apollo 11, Im sure that, if they didnt hear that, theyll get the word through the news. Among the very few items that Neil Armstrong carried with him to the Moon. In 1947, at age 17, Armstrong began studying engineering at Purdue University. He was the person in his family to attend college. He was also accepted to the Massachusetts Institute of Technology, the only engineer he knew dissuaded him from attending, telling Armstrong that it was not necessary to go all the way to Cambridge, Massachusetts, for a good education
15.
Buzz Aldrin
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Buzz Aldrin is an American engineer and former astronaut. As the Lunar Module Pilot on Apollo 11, he was one of the first two humans to land on the Moon, and the person to walk on it. He set foot on the Moon at 03,15,16 on July 21,1969 and he is a former U. S. Air Force officer with the Command Pilot rating. Aldrin was born January 20,1930, in Mountainside Hospital, in Glen Ridge and his parents were Edwin Eugene Aldrin Sr. a career military man, and Marion Aldrin, who lived in neighboring Montclair. He is of Scottish, Swedish, and German ancestry, Aldrin was a Boy Scout and earned the rank of Tenderfoot Scout. The nickname Buzz originated in childhood, the younger of his two elder sisters mispronounced brother as buzzer, and this was shortened to Buzz, Aldrin made it his legal first name in 1988. Aldrin graduated third in his class at West Point in 1951 with a Bachelor of Science degree in mechanical engineering and he was commissioned as a Second Lieutenant in the United States Air Force and served as a jet fighter pilot during the Korean War. He flew 66 combat missions in F-86 Sabres and shot down two Mikoyan-Gurevich MiG-15 aircraft, the June 8,1953, issue of Life magazine featured gun camera photos taken by Aldrin of one of the Soviet pilots ejecting from his damaged aircraft. That same year, he graduated from the Squadron Officer School at Maxwell Air Force Base in Alabama and he flew F-100 Super Sabres as a flight commander at Bitburg Air Base, West Germany, in the 22d Fighter Squadron. In January 1963, Aldrin earned a Sc. D. degree in astronautics from the Massachusetts Institute of Technology, if only I could join them in their exciting endeavors. On completion of his doctorate, he was assigned to the Gemini Target Office of the Air Force Space Systems Division in Los Angeles before his selection as an astronaut, Aldrin was selected as a member of the third group of NASA astronauts in October 1963. Because test pilot experience was no longer a requirement, this was the first selection for which he was eligible, after the deaths of the original Gemini 9 prime crew, Elliot See and Charles Bassett, Aldrin and Jim Lovell were promoted to backup crew for the mission. He was confirmed as pilot on Gemini 12, the last Gemini mission and he set a record for EVA, demonstrating that astronauts could work outside spacecraft. Aldrin was chosen for the crew of Apollo 11 and made the first lunar landing with commander Neil Armstrong on July 20,1969. The next day, Aldrin became the person to walk on the Moon. Aldrins first words on the Moon were Beautiful view, then, in response to Armstrong asking, Isnt it magnificent. He was also the first person to urinate while on the Moon, there has been speculation about the extent of Aldrins desire at the time to be the first astronaut to walk on the Moon and its impact on his pre-flight, in-mission and post-flight actions. Also, Armstrong was the Mission Commander, and other astronauts who would command later Apollo missions were not sympathetic to Aldrins views
16.
Michael Collins (astronaut)
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Michael Collins, is an American former astronaut and test pilot. Selected as part of the group of fourteen astronauts in 1963. His first spaceflight was on Gemini 10, in which he and his second spaceflight was as the Command Module Pilot for Apollo 11. While he stayed in orbit around the Moon, Neil Armstrong and he is one of 24 people to have flown to the Moon. Collins was the person, and third American, to perform an EVA. Prior to becoming an astronaut, he attended the United States Military Academy and he was accepted to the U. S. Air Force Experimental Flight Test Pilot School at Edwards Air Force Base in 1960. He unsuccessfully applied for the astronaut group, but was accepted for the third group. After retiring from NASA in 1970 he took a job in the Department of State as Assistant Secretary of State for Public Affairs, a year later he became the director of the National Air and Space Museum. He held this position until 1978 when he stepped down to become undersecretary of the Smithsonian Institution, in 1980 he took the job as Vice President of LTV Aerospace. He resigned in 1985 to start his own business and he was married to Patricia Collins until her death in April 2014. They had three children, Kate, Ann, and Michael, Collins was born in Rome, Italy, on October 31,1930, to U. S. Army Major General James Lawton Collins, who served in the army for 38 years. For the first 17 years of his life, Collins called Rome, Oklahoma, Governors Island, New York, Puerto Rico, San Antonio, Texas and he took his first ride in a plane in Puerto Rico aboard a Grumman Widgeon. His father often told of how his own first plane ride had been in 1911 with Frank Lahm in the Philippines and he studied for two years in the Academia del Perpetuo Socorro in San Juan, Puerto Rico. After the United States entered World War II, the moved to Washington, D. C. where Collins attended St. Albans School. He graduated with a Bachelor of Science degree, finishing 185th out of 527 cadets in 1952, Lawton Collins, was the Chief of Staff of the United States Army. The Air Force Academy was in its construction phase. In the interim, graduates of the Military Academy, Naval Academy and he was chosen for advanced day fighter training at Nellis Air Force Base, Nevada, flying F-86 Sabres. This was followed by an assignment to the 21st Fighter-Bomber Wing at George Air Force Base, California and he transferred with the 21st when it was relocated to Chaumont-Semoutiers Air Base, France, in June 1954
17.
Apollo 11
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Apollo 11 was the spaceflight that landed the first two humans on the Moon. Mission commander Neil Armstrong and pilot Buzz Aldrin, both American, landed the lunar module Eagle on July 20,1969, at 20,18 UTC. Armstrong became the first to step onto the lunar surface six hours later on July 21 at 02,56,15 UTC and they spent about two and a quarter hours together outside the spacecraft, and collected 47.5 pounds of lunar material to bring back to Earth. Michael Collins piloted the command module Columbia alone in lunar orbit while they were on the Moons surface, Armstrong and Aldrin spent just under a day on the lunar surface before rendezvousing with Columbia in lunar orbit. Apollo 11 was launched by a Saturn V rocket from Kennedy Space Center in Merritt Island, Florida, on July 16, and was the fifth manned mission of NASAs Apollo program. After being sent toward the Moon by the Saturn Vs upper stage, Armstrong and Aldrin then moved into the lunar module Eagle and landed in the Sea of Tranquility. They stayed a total of about 21.5 hours on the lunar surface, the astronauts used Eagles upper stage to lift off from the lunar surface and rejoin Collins in the command module. They jettisoned Eagle before they performed the maneuvers that blasted them out of orbit on a trajectory back to Earth. They returned to Earth and landed in the Pacific Ocean on July 24, broadcast on live TV to a worldwide audience, Armstrong stepped onto the lunar surface and described the event as one small step for man, one giant leap for mankind. Apollo 11 was the second all-veteran multi-person crew in human spaceflight history, a previous solo veteran flight had been made on Soyuz 1 in 1967 by Soviet cosmonaut Vladimir Komarov. Collins was originally slated to be the Command Module Pilot on Apollo 8 but was removed when he required surgery on his back and was replaced by Jim Lovell, his backup for that flight. In early 1969, Anders accepted a job with the National Space Council effective August 1969, charlie Duke, Capsule Communicator Ronald Evans Owen K. Garriott Don L. Low to suggest the Apollo 11 crew be less flippant in naming their craft. During early mission planning, the names Snowcone and Haystack were used and put in the news release, the Command Module was named Columbia after the Columbiad, the giant cannon shell spacecraft fired by a giant cannon in Jules Vernes 1865 novel From the Earth to the Moon. The Lunar Module was named Eagle for the bird of the United States, the bald eagle. The Apollo 11 mission insignia was designed by Collins, who wanted a symbol for peaceful lunar landing by the United States and he chose an eagle as the symbol, put an olive branch in its beak, and drew a lunar background with the Earth in the distance. NASA officials said the talons of the eagle looked too warlike and after some discussion, All colors are natural, with blue and gold borders around the patch. When the Eisenhower dollar coin was released in 1971, the design provided the eagle for its reverse side. The design was used for the smaller Susan B
18.
Pyroxferroite
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Pyroxferroite SiO3 is a single chain inosilicate. It is mostly composed of iron, silicon and oxygen, with fractions of calcium. Together with armalcolite and tranquillityite, it is one of the three minerals which were discovered on the Moon and it was then found in Lunar and Martian meteorites as well as a mineral in the Earths crust. Pyroxferroite can also be produced by annealing synthetic clinopyroxene at high pressures and temperatures, the mineral is metastable and gradually decomposes at ambient conditions, but this process can last billions of years. Pyroxferroite is named from pyroxene and ferrum, as the analogue of pyroxmangite. The word pyroxene, in comes from the Greek words for fire. However, they are simply early-forming minerals that crystallized before the lava erupted, pyroxferroite was first discovered in 1969 in lunar rock samples from the Sea of Tranquility during the Apollo missions. Together with armalcolite and tranquillityite, it is one of the three minerals which were first found on the Moon, later, pyroxferroite was detected in Lunar and Martian meteorites recovered in Oman. Pyroxferroite has been found in the Isanago mine, in Kyoto Prefecture, Japan, near Iva, Anderson County, South Carolina, USA, from Vaaster Silfberg, Vaarmland, Sweden, and Lapua, Finland. In the original samples, pyroxferroite was associated with similar minerals, but also with troilite which is rare on Earth. Synthetic pyroxferroite crystals can be produced by compressing synthetic clinopyroxene to a pressure in the range of 10–17.5 kbar, however, the conversion rate is very slow and pyroxferroite can exist at low temperatures for periods longer than 3 billion years. The crystal structure of pyroxferroite contains silicon-oxygen chains with a period of seven SiO4 tetrahedra. These chains are separated by polyhedra where a metal atom is surrounded by 6 or 7 oxygen atoms. The resulted layers are parallel to planes in pyroxferroite, whereas they are parallel to planes in pyroxenes, chemical composition of pyroxferroite can be decomposed into elementary oxides as follows, FeO, SiO2, CaO, MnO, MgO, TiO2 and Al2O3. Whereas magnesium is present at about 0. 8%, in some samples it had an undetectably low concentration
19.
Ilmenite
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Ilmenite is the titanium-iron oxide mineral with the idealized formula FeTiO3. It is a weakly magnetic black or steel-gray solid, from the commercial perspective, ilmenite is the most important ore of titanium. Ilmenite is the source of titanium dioxide, which is used in paints, fabrics, plastics, paper, sunscreen, food. Ilmenite crystallizes in the trigonal system, containing high spin ferrous centers, ilmenite is paramagnetic. Ilmenite is commonly recognized in altered igneous rocks by the presence of an alteration product. Often ilmenites are rimmed with leucoxene, which allows ilmenite to be distinguished from magnetite, the example shown in the image at right is typical of leucoxene-rimmed ilmenite. In reflected light it may be distinguished from magnetite by more pronounced reflection pleochroism, samples of ilmenite exhibit a weak response to a hand magnet. Ilmenite most often contains appreciable quantities of magnesium and manganese and the chemical formula can be expressed as O3. Ilmenite forms a solution with geikielite and pyrophanite which are magnesian. At higher temperatures it has been demonstrated there is a solid solution between ilmenite and hematite. There is a miscibility gap at lower temperatures, resulting in a coexistence of two minerals in rocks but no solid solution. This coexistence may result in exsolution lamellae in cooled ilmenites with more iron in the system than can be accommodated in the crystal lattice. Altered ilmenite forms the mineral leucoxene, an important source of titanium in heavy mineral sands ore deposits, leucoxene is a typical component of altered gabbro and diorite and is generally indicative of ilmenite in the unaltered rock. Ilmenite is an accessory mineral found in metamorphic and igneous rocks. It is found in large concentrations in layered intrusions where it forms as part of a layer within the silicate stratigraphy of the intrusion. Ilmenite generally occurs within the portion of such intrusions. Magnesian ilmenite is indicative of kimberlitic paragenesis and forms part of the MARID association of minerals assemblage of glimmerite xenoliths, manganiferous ilmenite is found in granitic rocks and also in carbonatite intrusions where it may also contain anomalous niobium. Many mafic igneous rocks contain grains of magnetite and ilmenite
20.
Rutile
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Rutile is a mineral composed primarily of titanium dioxide, TiO2. Rutile is the most common form of TiO2. Three rarer polymorphs of TiO2 are known, Anatase, a metastable tetragonal mineral of pseudo-octahedral habit Brookite, an orthorhombic mineral TiO2, rutile has among the highest refractive indices at visible wavelengths of any known crystal, and also exhibits a particularly large birefringence and high dispersion. Owing to these properties, it is useful for the manufacture of optical elements, especially polarization optics, for longer visible. Natural rutile may contain up to 10% iron and significant amounts of niobium and tantalum, rutile derives its name from the Latin rutilus, red, in reference to the deep red color observed in some specimens when viewed by transmitted light. Rutile is an accessory mineral in high-temperature and high-pressure metamorphic rocks. Thermodynamically, rutile is the most stable polymorph of TiO2 at all temperatures, consequently, the transformation of the metastable TiO2 polymorphs to rutile is irreversible. As it has the lowest molecular volume of the three polymorphs, it is generally the primary titanium bearing phase in most high-pressure metamorphic rocks. The occurrence of large specimen crystals is most common in pegmatites, skarns, rutile is found as an accessory mineral in some altered igneous rocks, and in certain gneisses and schists. In groups of acicular crystals it is frequently seen penetrating quartz as in the fléches damour from Graubünden, in 2005 the Republic of Sierra Leone in West Africa had a production capacity of 23% of the worlds annual rutile supply, which rose to approximately 30% in 2008. The reserves, lasting for about 19 years, are estimated at 259,000,000 metric tons, rutile has a body-centred tetragonal unit cell, with unit cell parameters a=b=4.584 Å, and c=2.953 Å. The titanium cations have a number of 6 meaning they are surrounded by an octahedron of 6 oxygen atoms. The oxygen anions have a number of 3 resulting in a trigonal planar co-ordination. Rutile also shows a screw axis when its octahedra are viewed sequentially, rutile crystals are most commonly observed to exhibit a prsimatic or acicular growth habit with preferential orientation along their c-axis, the direction. This growth habit is favored as the facets of rutile exhibit the lowest surface free energy and are therefore thermodynamically most stable, the c-axis oriented growth of rutile appears clearly in nanorods, nanowires and Abnormal grain growth phenomena of this phase. In large enough quantities in beach sands, rutile forms an important constituent of heavy minerals, miners extract and separate the valuable minerals—e. g. The main uses for rutile are the manufacture of ceramic, as a pigment. Finely powdered rutile is a brilliant white pigment and is used in paints, plastics, paper, foods, titanium dioxide pigment is the single greatest use of titanium worldwide
21.
Mare Tranquillitatis
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Mare Tranquillitatis is a lunar mare that sits within the Tranquillitatis basin on the Moon. The mare material within the basin consists of basalt formed in the intermediate to young age group of the Upper Imbrian epoch, the surrounding mountains are thought to be of the Lower Imbrian epoch, but the actual basin is probably Pre-Nectarian. The basin has irregular margins and lacks a defined multiple-ringed structure, palus Somni, on the northeastern rim of the mare, is filled with the basalt that spilled over from Tranquillitatis. This Mare has a bluish tint relative to the rest of the moon. The color is due to higher metal content in the basaltic soil or rocks. Unlike many other maria, there is no mass concentration, or gravitational high, mascons were identified in the center of other maria from Doppler tracking of the five Lunar Orbiter spacecraft in 1968. The gravity field was mapped at higher resolution with later orbiters such as Lunar Prospector and GRAIL, Mare Tranquillitatis was named in 1651 by astronomers Francesco Grimaldi and Giovanni Battista Riccioli in their lunar map Almagestum novum. Surveyor 5 landed in Mare Tranquillitatis on September 11,1967 and this mare was also the landing site for the first crewed landing on the Moon on July 20,1969, at 20,18 UTC. After astronauts Neil Armstrong and Buzz Aldrin made a touchdown in the Apollo 11 Lunar Module named Eagle, Armstrong told flight controllers on Earth, Houston. The landing area at 0. 8° N,23, along the periphery of the mare are several bay-shaped features that have been given names, Sinus Amoris, Sinus Asperitatis, Sinus Concordiae, and Sinus Honoris. At the left is the east side of Mare Tranquillitatis, with the craters Franz, Lyell, the bay of dark mare at left is Sinus Concordiae, with islands of older, light highland material. At right is the crater Cauchy, which lies between the Rupes Cauchy and Cauchy rille, the center photo shows the central mare with craters Vitruvius and Gardner. At the horizon are lighter highlands at the margin of the mare. The crater Jansen is visible at the edges of both the center and right photos, the right photo shows the western mare, with the craters Dawes and the large Plinius, with the Plinius Rilles in the foreground. These photos were taken within minutes of each other as the Command Module America orbited the moon, the sun elevation drops from 46 degrees at left to 30 degrees at right. Israeli psych-progressive rock band Jericho Jones recorded a song named Mare Tranquilitatas as the track of their UK album release Junkies. The band is known as The Churchills. Mare Tranquillitatis is also the name of a composition of music by composer Vangelis on his 1976 album, Sea of Tranquility is also a song by the progressive rock band Barclay James Harvest, included in their 1977 album Gone to Earth
22.
Descartes Highlands
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The Descartes Highlands is an area of lunar highlands located on the near side that served as the landing site of the American Apollo 16 mission in early 1972. The Descartes Highlands is located in the area surrounding Descartes crater, after which the received its name. Two major formations dominate the Descartes Highlands area, the Cayley plains, the latter is composed primarily of highland plateau material, perhaps debris from large impact events. North Ray and South Ray craters, the former sampled directly by the Apollo 16 crew, revealed a sequence, possibly an overlap of the Cayley. The area of the Descartes Highlands is characterized by a landscape covered with old and some new. Based upon findings during the Apollo 16 mission, some of the floors of craters were covered with glass similar to that found at the Taurus-Littrow landing site on Apollo 17. According to Apollo 16 commander John Young, the arrangement of the glass gave it the appearance of dried mud, before Apollo 16 sampled the Descartes Highlands, it was believed that volcanic material would be abundant in the area after visual analysis of the features there. It was thought that the formations in the area were formed by more viscous than the lavas that formed the Lunar mare. This was later disproved after the analysis of samples from the area and it was revealed that many of the rocks in the area are not volcanic in origin, but breccias composed of fragments from several lunar impacts. Astronauts Young and Duke visited Sudbury, Ontario Canada in July 1971 to examine shatter cones, Sudbury is a site of a large meteor impact exhibiting substantial evidence of shatter cone geology. In the Descartes Highlands, it was determined that the topography was formed by meteor impact instead of volcanic activity. All of the preceding Apollo landing missions sampled Lunar mare material, a landing site in the Lunar highlands was to be selected with the goal of investigating the material located there. Two landing sites were given consideration to achieve this goal, the Descartes site, sampling these formations was a priority, as the two cover much of the near side of the Moon. Apollo 16 Big Muley Geology of the Moon Descartes
23.
Lamproite
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Lamproites are ultrapotassic mantle-derived volcanic and subvolcanic rocks. They have low CaO, Al2O3, Na2O, high K2O/Al2O3, Lamproites are geographically widespread yet are volumetrically insignificant. They also vary widely in age, from Proterozoic to Pleistocene, lamproite volcanology is varied, with both diatreme styles and cinder cone or cone edifices known. Lamproites form from partially melted mantle at depths exceeding 150 km and this observation also reconciles the depth of melting with the peculiar geochemistry, which is most easily explained by melting of already felsic material under deep mantle conditions. The mineralogy of lamproites is controlled by their peculiar geochemistry, with a predominance of rare silica-deficient mineral species and rare, a variety of rare trace minerals occur. The rocks are high in potassium with 6 to 8% potassium oxide, high chromium and nickel content is typical. The rocks commonly are altered to talc with carbonate or serpentine, chlorite, zeolites and quartz may also occur. The presence of all the phases is not required in order to classify a rock as a lamproite. Any one mineral may be dominant, and this, together with the two or three other minerals present, suffices to determine the petrographic name. The economic significance of lamproite became known with the 1979 discovery of the Argyle diamond pipe in Western Australia and this discovery led to the intense study and re-evaluation of other known lamproite occurrences worldwide, previously only kimberlite pipes were considered economically viable sources of diamonds. The Argyle diamond mine remains the only economically viable source of lamproite diamonds and this deposit differs markedly by having a high content of diamonds but low quality of most stones. Research at Argyle diamond have shown that most stones are of E-type, the Argyle diamond mine is the main source of rare pink diamonds. Olivine lamproite pyroclastic rocks and dikes are sometimes hosts for diamonds, the diamonds occur as xenocrysts that have been carried to the surface or to shallow depths by the lamproite diapiric intrusions. The diamonds of Crater of Diamonds State Park near Murfreesboro, Arkansas are found in a lamproite host, modern terminology classes all as lamproites but modifies this term with the mineral abundances as per the standard IUGS rules. Kimberlite Lamprophyre Ultrapotassic igneous rocks Bergman, S. C,1987, Lamproites and other potassium-rich igneous rocks, a review of their occurrences, mineralogy and geochemistry. In, Alkaline Igneous rocks, Fitton, J. G. and Upton, B. G. J, Mitchell, R. H. Bergman, S. C. Murphy, D. T. Collerson, K. D. Kamber, B. S. Lamproites from Gaussberg, Antarctica, edgar, A. D, Le Bas, M. J. Mitchell, R. H. Rock, N. M. S. Classification of lamprophyres, lamproites, kimberlites, and the kalsilitic, melilitic, the Canadian Mineralogist, Vol 34, Part 2
24.
Dike (geology)
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A dike or dyke, in geological usage, is a sheet of rock that formed in a fracture in a pre-existing rock body. Dikes can be either magmatic or sedimentary in origin, magmatic dikes form when magma intrudes into a crack then crystallizes as a sheet intrusion, either cutting across layers of rock or through an unlayered mass of rock. Clastic dikes are formed when sediment fills a pre-existing crack, an intrusive dike is an igneous body with a very high aspect ratio, which means that its thickness is usually much smaller than the other two dimensions. Thickness can vary from sub-centimeter scale to many meters, and the dimensions can extend over many kilometres. A dike is an intrusion into an opening cross-cutting fissure, shouldering aside other pre-existing layers or bodies of rock, near-horizontal, or conformable intrusions, along bedding planes between strata are called intrusive sills. Sometimes dikes appear in swarms, consisting of several to hundreds of dikes emplaced more or less contemporaneously during a single intrusive event, the worlds largest dike swarm is the Mackenzie dike swarm in the Northwest Territories, Canada. Dikes often form as either radial or concentric swarms around plutonic intrusives, the latter are known as ring dikes. Pegmatite dikes comprise extremely coarse crystalline granitic rocks - often associated with granite intrusions or metamorphic segregations. Aplite dikes are fine-grained or sugary-textured intrusives of granitic composition, in contrast to magmatic dikes, a sill is a magmatic sheet intrusion that forms within and parallel to the bedding of layered rock. Sedimentary dikes or clastic dikes are vertical bodies of rock that cut off other rock layers. Driven by the pressure the sediment breaks through overlying layers. When a soil is under permafrost conditions the water is totally frozen. When cracks are formed in rocks, they may fill up with sediments that fall in from above. The result is a body of sediment that cuts through horizontal layers. Batholith Ring dike Fissure vent Laccolith Runamo, formerly interpreted as a runic inscription
25.
Garfield County, Montana
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Garfield County is a county located in the U. S. state of Montana. As of the 2010 census, the population was 1,206, Garfield County is noteworthy as the site of the discovery and excavation of four of the worlds dozen or so major specimens of Tyrannosaurus rex within the county. A cast of the skull of one of these dinosaurs is on display at the Garfield County Museum. According to the U. S. Census Bureau, the county has an area of 4,847 square miles. Its average population density of 0.1058 inhabitants/km² is the third-lowest of any county outside of Alaska, russell National Wildlife Refuge As of the census of 2000, there were 1,279 people,532 households, and 366 families residing in the county. There were 961 housing units at a density of <1/km². The racial makeup of the county was 99. 14% White,0. 08% Black or African American,0. 39% Native American,0. 08% Asian,0. 08% Pacific Islander,0. 39% of the population were Hispanic or Latino of any race. 25. 9% were of German,15. 4% English,14. 4% American,8. 1% Scottish,8. 1% Irish,6. 7% Norwegian and 5. 5% Scots-Irish ancestry. 28. 20% of all households were made up of individuals and 13. 50% had someone living alone who was 65 years of age or older, the average household size was 2.38 and the average family size was 2.93. In the county, the population was out with 24. 50% under the age of 18,7. 10% from 18 to 24,23. 30% from 25 to 44,25. 80% from 45 to 64. The median age was 42 years, for every 100 females there were 106.60 males. For every 100 females age 18 and over, there were 103.40 males, the median income for a household in the county was $25,917, and the median income for a family was $31,111. Males had an income of $20,474 versus $14,531 for females. The per capita income for the county was $13,930, about 16. 70% of families and 21. 50% of the population were below the poverty line, including 27. 90% of those under age 18 and 17. 40% of those age 65 or over. As of the 2010 United States Census, there were 1,206 people,532 households, the population density was 0.3 inhabitants per square mile. There were 844 housing units at a density of 0.2 per square mile. The racial makeup of the county was 98. 6% white,0. 4% American Indian,0. 2% black or African American,0. 1% Asian,0. 2% from other races, and 0. 5% from two or more races. Those of Hispanic or Latino origin made up 0. 2% of the population
26.
United States
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Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography, climate and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power. The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations. In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci
27.
Bavaria
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Bavaria is a free state and one of 16 federal states of Germany. Located in the German southeast with an area of 70,548 square kilometres and its territory comprises roughly a fifth of the total land area of Germany, and, with 12.9 million inhabitants, it is Germanys second most populous state. Munich, Bavarias capital and largest city, is the third largest city in Germany, the Duchy of Bavaria dates back to the year 555. In the 17th century CE, the Duke of Bavaria became a Prince-elector of the Holy Roman Empire, the Kingdom of Bavaria existed from 1806 to 1918, when Bavaria became a republic. In 1946, the Free State of Bavaria re-organised itself on democratic lines after the Second World War, Bavaria has a unique culture, largely because of the states Catholic majority and conservative traditions. Bavarians have traditionally been proud of their culture, which includes such as Oktoberfest. The state also has the second largest economy among the German states by GDP figures, modern Bavaria also includes parts of the historical regions of Franconia, Upper Palatinate and Swabia. The Bavarians emerged in a north of the Alps, previously inhabited by Celts. The Bavarians spoke Old High German but, unlike other Germanic groups, rather, they seem to have coalesced out of other groups left behind by Roman withdrawal late in the 5th century. These peoples may have included the Celtic Boii, some remaining Romans, Marcomanni, Allemanni, Quadi, Thuringians, Goths, Scirians, Rugians, the name Bavarian means Men of Baia which may indicate Bohemia, the homeland of the Celtic Boii and later of the Marcomanni. They first appear in written sources circa 520, a 17th century Jewish chronicler David Solomon Ganz, citing Cyriacus Spangenberg, claimed that the diocese was named after an ancient Bohemian king, Boiia, in the 14th century BCE. From about 554 to 788, the house of Agilolfing ruled the Duchy of Bavaria and their daughter, Theodelinde, became Queen of the Lombards in northern Italy and Garibald was forced to flee to her when he fell out with his Frankish overlords. Garibalds successor, Tassilo I, tried unsuccessfully to hold the frontier against the expansion of Slavs. Tassilos son Garibald II seems to have achieved a balance of power between 610 and 616, after Garibald II little is known of the Bavarians until Duke Theodo I, whose reign may have begun as early as 680. From 696 onwards he invited churchmen from the west to organize churches and his son, Theudebert, led a decisive Bavarian campaign to intervene in a succession dispute in the Lombard Kingdom in 714, and married his sister Guntrud to the Lombard King Liutprand. At Theodos death the duchy was divided among his sons, at Hugberts death the duchy passed to a distant relative named Odilo, from neighbouring Alemannia. He was defeated near Augsburg in 743 but continued to rule until his death in 748, saint Boniface completed the peoples conversion to Christianity in the early 8th century. Bavaria was in ways affected by the Protestant Reformation in the 16th century
28.
Greenland
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Greenland is an autonomous constituent country within the Danish Realm between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for more than a millennium. The majority of its residents are Inuit, whose ancestors began migrating from the Canadian mainland in the 13th century, Greenland is the worlds largest island. Three-quarters of Greenland is covered by the permanent ice sheet outside Antarctica. With a population of about 56,480, it is the least densely populated country in the world, the Arctic Umiaq Line ferry acts as a lifeline for western Greenland, connecting the various cities and settlements. Greenland has been inhabited off and on for at least the last 4,500 years by Arctic peoples whose forebears migrated there from what is now Canada, Norsemen settled the uninhabited southern part of Greenland beginning in the 10th century, and Inuit peoples arrived in the 13th century. The Norse colonies disappeared in the late 15th century, soon after their demise, beginning in 1499, the Portuguese briefly explored and claimed the island, naming it Terra do Lavrador. In the early 18th century, Scandinavian explorers reached Greenland again, to strengthen trading and power, Denmark-Norway affirmed sovereignty over the island. Greenland was settled by Vikings more than a thousand years ago, Vikings set sail from Greenland and Iceland, discovering North America nearly 500 years before Columbus reached Caribbean islands. Though under continuous influence of Norway and Norwegians, Greenland was not formally under the Norwegian crown until 1262, the Kingdom of Norway was extensive and a military power until the mid-14th century. Thus, the two kingdoms resources were directed at creating Copenhagen, Norway became the weaker part and lost sovereignty over Greenland in 1814 when the union was dissolved. Greenland became a Danish colony in 1814, and was made a part of the Danish Realm in 1953 under the Constitution of Denmark, in 1973, Greenland joined the European Economic Community with Denmark. However, in a referendum in 1982, a majority of the population voted for Greenland to withdraw from the EEC which was effected in 1985, Greenland contains the worlds largest and most northernly national park, Northeast Greenland National Park. Greenland is divided into four municipalities - Sermersooq, Kujalleq, Qaasuitsup and it also retains control of monetary policy, providing an initial annual subsidy of DKK3.4 billion, which is planned to diminish gradually over time. Greenland expects to grow its economy based on increased income from the extraction of natural resources, the capital, Nuuk, held the 2016 Arctic Winter Games. At 70%, Greenland has one of the highest shares of renewable energy in the world, the early Viking settlers named the island as Greenland. In the Icelandic sagas, the Norwegian-born Icelander Erik the Red was said to be exiled from Iceland for manslaughter, along with his extended family and his thralls, he set out in ships to explore an icy land known to lie to the northwest. After finding an area and settling there, he named it Grœnland
29.
Disko Island
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Disko Island is a large island in Baffin Bay, off the west coast of Greenland. It has an area of 8,578 km2, making it the second largest island of Greenland, the name Qeqertarsuaq means The Large Island. The island has a length of about 160 km, rising to an height of 975 m. The port of Qeqertarsuaq lies on its southern coast, blæsedalen valley is north of Qeqertarsuaq. The island is separated from Nuussuaq Peninsula in the northeast by the Sullorsuaq Strait, to the south of the island lies Disko Bay, an inlet bay of Baffin Island. Eric the Red paid the first recorded visit to Disko Island at some time between 982 and 985, the island may have used as a base for summer hunting and fishing by Viking colonists. Mineral deposits, fossil finds and geological formations add to interest in the area, one of the interesting geological features is the native iron found at the island. A 22-ton lump mixture of iron and iron carbide has been found, there are only a few places on earth where native iron is found which is not of meteoric origin. There are numerous hot springs on the island, the microscopic animal Limnognathia, the only known member of its phylum, was discovered in these springs. Several studies on the show high marine interstitial diversity in Disko Island. For instance, the gastrotrich species Diuronotus aspetos is found in Iterdla and it is associated with a rich diversity of other gastrotrichs like Chatonotus atrox, Halichaetonotus sp
30.
Kimberlite
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Kimberlite is an igneous rock best known for sometimes containing diamonds. Kimberlite occurs in the Earths crust in vertical structures known as kimberlite pipes as well as igneous dykes, Kimberlite also occurs as horizontal sills. Kimberlite pipes are the most important source of mined diamonds today, the consensus on kimberlites is that they are formed deep within the mantle. It is this depth of melting and generation which makes kimberlites prone to hosting diamond xenocrysts, despite its relative rarity, kimberlite has attracted attention because it serves as a carrier of diamonds and garnet peridotite mantle xenoliths to the Earths surface. Many kimberlite structures are emplaced as carrot-shaped, vertical intrusions termed pipes, Kimberlite classification is based on the recognition of differing rock facies. These differing facies are associated with a style of magmatic activity, namely crater, diatreme. The morphology of kimberlite pipes, and their classical carrot shape is the result of explosive volcanism from very deep mantle-derived sources. These volcanic explosions produce vertical columns of rock rise from deep magma reservoirs. The morphology of kimberlite pipes is varied but includes a sheeted dyke complex of tabular, within 1. 5–2 km of the surface, the highly pressured magma explodes upwards and expands to form a conical to cylindrical diatreme, which erupts to the surface. The surface expression is rarely preserved but is similar to a maar volcano. The diameter of a pipe at the surface is typically a few hundred meters to a kilometer. Two Jurassic kimberlite dikes exist in Pennsylvania, one, the Gates-Adah Dike, outcrops on the Monongahela River on the border of Fayette and Greene Counties. The other, the Dixonville-Tanoma Dike in central Indiana County, does not outcrop at the surface and was discovered by miners, similarly aged kimberlite is found in several locations in New York Both the location and origin of kimberlitic magmas are subjects of contention. The mechanism of enrichment has also been the topic of interest with models including partial melting, historically, kimberlites have been classified into two distinct varieties termed basaltic and micaceous based primarily on petrographic observations. This was later revised by Smith who renamed these divisions Group I and Group II based on the affinities of these rocks using the Nd, Sr. Mitchell later proposed that these group I and II kimberlites display such distinct differences and he showed that Group II kimberlites show closer affinities to lamproites than they do to Group I kimberlites. Hence, he reclassified Group II kimberlites as orangeites to prevent confusion, olivine lamproites were previously called Group II kimberlite or orangeite in response to the mistaken belief that they only occurred in South Africa. Their occurrence and petrology, however, are identical globally and should not be referred to as kimberlite
31.
Province of Albacete
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Albacete is a province of central Spain, in the southern part of the autonomous community of Castile–La Mancha. As of 2012, Albacete had a population of 402,837 people and its capital lies at Albacete,262 kilometres by road southeast of Madrid. The territory occupied by the province of Albacete has been inhabited since ancient times, as evidenced by cave paintings in the Cueva del Niño, in Roman times, the territory of the present province of Albacete was part of Carpetania and Celtiberia, Contestania, Bastetania and Oretania. In Roman times, the Romans built a significant settlement at Libisosa, during the Muslim era, territories of the province were under different zones of influence, and numerous farmhouses, castles and watchtowers developed to fight off invaders. In 1822 the province of ephemeral Province of Chinchilla was created, composed of municipalities in the provinces of La Mancha, Cuenca and the Kingdom of Murcia. Its capital at Chinchilla de Monte-Aragón, very close to the city of Albacete, following the adoption of the Constitution in 1978, the province of Albacete joined the Castile-La Mancha Region from the Murcia Region, and its Statute of Autonomy was approved in 1982. The province is divided into 87 municipalities and seven judicial districts and its seat of government is Albacete. Other important towns are, Hellín, Villarrobledo, Almansa, La Roda, the main river of the province is the Jucar river, which crosses the province in the northeast, renowned for its deep gorges and trees. The Lagunese de Ruidera flows in the west. and Taibilla rivers in the south
32.
Region of Murcia
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The Region of Murcia is an autonomous community of Spain located in the southeast of the state, between Andalusia and Valencian Community, on the Mediterranean coast. The autonomous community consists of a province, unlike most autonomous communities. Because of this, the community and the province are operated as one unit of government. The city of Murcia is the capital of the region and seat of government organs, except for the parliament, the Regional Assembly of Murcia, the autonomous community and province is subdivided into municipalities. The Region of Murcia is bordered by Andalusia, Castile–La Mancha, the Valencian Community, the community measures 11,313 km² and has a population of 1.4 million, of whom one-third live in the capital. The highest mountain is Los Obispos, the region is a major producer of fruits, vegetables, and flowers for the rest of Spain and Europe. Wineries have developed near the towns of Bullas, Yecla, and Jumilla, Murcia is mainly a warm region which has made it very suitable for agriculture. The region is located in the part of the Cordilleras Béticas mountains. These mountain ranges are divided as well in the Prebética, Subbética and Penibética mountain ranges, approximately 27% of the Murcian territory can be described as mountainous, 38% as intramountainous depressions and running valleys, and the remaining 35% as flat lands and plateaux. The Region of Murcia enjoys a Mediterranean climate of semi-arid type, with mild winters, the average annual temperature is 18 °C. With little precipitation of about 300 to 350 mm per year, april and October are the months with the most precipitation, there being frequent heavy downpours in a single day. The city of Murcia holds the temperature of the 20th century in Spain. It reached 46.1 °C on July 4,1994, the winter of 2005 was the coldest in a long time, with snow even falling on the Murcian coast. The hydrographic network of the region is made up of the Segura river and its affluents, Mundo, alhárabe and its affluent, the Benamor. Due to the water supplying incapacity of the Segura river basin, contributions to this basin are made, originated from the basin of the Tajo river. The greatest natural lake of Spain can be found in the region and it is a salt water lagoon, adjacent to the Mediterranean Sea. Its special ecological and natural characteristics make the Mar Menor a unique natural place, with a semicircular shape, it is separated from the Mediterranean Sea by a sand strip 22 km in length and between 100 and 1200 m wide, known as La Manga del Mar Menor. The lagoon has been designated by the United Nations as a Specially Protected Zone of Importance for the Mediterranean and its coastal perimeter accounts for 73 km of coast in which beaches follow one another with crystal clear shallow water
33.
Uvalde County, Texas
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Uvalde County is a county located in the U. S. state of Texas. As of the 2010 census, its population was 26,405, the county was created in 1850 and organized in 1856. It is named for Juan de Ugalde, the Spanish governor of Coahuila, Uvalde County was founded by Reading Wood Black who also founded the city of Uvalde, Texas. Uvalde County comprises the Uvalde, TX Micropolitan Statistical Area, artifacts establish human habitation dating back to 7000 B. C. Evidence of a permanent Indian village on the Leona River at a place south of the Fort Inge site is indicated in the accounts of Fernando del Bosques exploration in 1675. Comanche, Tonkawa, Seminole and Lipan Apache continued hunting and raiding settlers into the 19th Century, in honor of his victory, the canyon area was thereafter called Cañon de Ugalde. French botanist Jean-Louis Berlandier visited the area in the late 1820s, james Bowie guided a group of silver prospectors into the area of north central Uvalde County in the 1830s. A trail used by General Adrián Wolls Mexican Army on its way to attack San Antonio in 1842 crossed the territory of Uvalde County, Fort Inge was established in 1849 to repress Indian depredations on the international border with Mexico, and was served by the Overland Southern Mail. One of the first settlers to the environs was William Washington Arnett, the Canyon de Ugalde Land Company, formed by land speculators in San Antonio in 1837, began purchasing headright grants in Uvalde County in the late 1830s. Reading Wood Black, who with a partner, Nathan L. Stratton, purchased an undivided league, may 2,1855, Black hired San Antonio lithographer Wilhelm Carl August Thielepape, and laid out Encina, the town later known as Uvalde. Waresville settlement by Capt. William Ware in the upper Sabinal Canyon and Patterson Settlement by George W. Patterson, John Leakey, dillard on the Sabinal River coincided with Reading Blacks development of the Leona River at Encina. In November 1855, Reading Wood Black successfully lobbied the Texas legislature to organize Uvalde County, on May 12, the county was formally organized. On June 14, Encina was named county seat, the second floor of the courthouse was made into a school, and six school districts were organized for the county in 1858. The San Antonio-El Paso Mail route was extended along the main road with a stop at Fort Inge in 1857. Conflict between Mexicans and Anglos during and after the Mexican War continued in Uvalde County, with the lynching of eleven Mexicans near the Nueces River in 1855. Laws passed in 1857 prohibited Mexicans from traveling through the county, residents of Uvalde County voted 76–16 against secession from the Union. The abandonment of Fort Inge immediately after secession was followed by renewed Indian attacks, many men in Uvalde County fought for the Confederacy, while some Unionists fled to Mexico to avoid persecution. Uvalde County endured three decades of unrelenting lawlessness after the Civil War, the years immediately following the Civil War were marked by conflicts between Confederates and Unionists returning to live in Uvalde County
34.
Jordan, Montana
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Jordan is a town in and the county seat of Garfield County, Montana, United States. The population was 343 at the 2010 census, originally settled in 1896, Jordan received a post office on July 11,1899. The founder, Arthur Jordan, had hunted the area a great deal, before very long a town began to spring up around the post office. There were saloons, rooming houses, livery stables, blacksmiths, in the later part of the 1910s the homestead boom hit Garfield County, which was then actually part of Dawson County to the east. By 1919, it became the consensus of many locals that they needed to form a county of their own, after much ado by competing towns in the area, Jordan was finally chosen as the county seat, by popular vote. Jordan was incorporated as a town in 1951, on March 25,1996 an 81-day-long standoff between the antigovernment Montana Freemen and federal officers began near here. Jordan is located at 47°19. 3′N 106°54. 6′W, according to the United States Census Bureau, the town has a total area of 0.34 square miles, all of it land. Jordan experiences a climate with long, cold, dry winters and hot. As of the census of 2010, there were 343 people,170 households, the population density was 1,008.8 inhabitants per square mile. There were 206 housing units at a density of 605.9 per square mile. The racial makeup of the town was 98. 8% White,0. 6% Native American,0. 3% from other races, hispanic or Latino of any race were 0. 9% of the population. 37. 6% of all households were made up of individuals and 18. 9% had someone living alone who was 65 years of age or older, the average household size was 2.02 and the average family size was 2.71. The median age in the town was 48.8 years. 18. 7% of residents were under the age of 18,6. 1% were between the ages of 18 and 24,19. 2% were from 25 to 44, 31% were from 45 to 64, and 25. 1% were 65 years of age or older. The gender makeup of the town was 49. 0% male and 51. 0% female, as of the census of 2000, there were 364 people,169 households, and 98 families residing in the town. The population density was 1,024.9 people per square mile, there were 233 housing units at an average density of 656.0 per square mile. The racial makeup of the town was 98. 63% White,0. 27% African American,0. 27% Pacific Islander, hispanic or Latino of any race were 1. 37% of the population. 39. 1% of all households were made up of individuals and 23. 1% had someone living alone who was 65 years of age or older, the average household size was 2.08 and the average family size was 2.80
35.
Mwenezi District
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Mwenezi is a small district situated in southern Zimbabwe. It is bisected by the Mwenezi River and the A4 highway, Mwenezi derives its name from the Mwenezi River, which provides irrigation water to the sugarcane plantations in and around the Rutenga Business Center. Although the police station is located along the highway, the administrative offices are located at the Neshuro Business Center. The weather is hot and dry throughout the year, except during the summer rain is frequent. In 2002, the population of the district was estimated to be 126,000, up by 25,000 from 1992. Mwenezi lies in natural regions four and five, the district is prone to droughts and experiences low mean annual rainfall. The majority of households in Mwenezi depend on agricultural production, like livestock rearing, as in other rural parts of the country, the schools in Mwenezi are government run, although some have historical links with missionary Christian denominations. There is one boarding school, Lundi Secondary School, the fact that all the secondary schools were established after independence, is testimony to the marginalization of the district and the catching up it needs to do. However, not all villages have secondary schools, some students, especially those from villages along the Mwenezi River, below the main wall of the Manyuchi Dam, have to walk long distances to school, about fifteen to twenty kilometers. This state of affairs discourages students from going to school, instead opting to cross the border, the districts main employers are sugarcane plantations in Rutenga, Triangle and Chiredzi all connected by a railway line from Bulawayo. The cattle ranchers, before the influx of commercial farms in 2000, as in most rural districts in the country, many people are also employed in the civil service mainly as teachers and nurses. The people in the district had always trekked to the mines of South Africa, however, the number of migrant workers has increased in recent times due to the economic recession that Zimbabwe has been going through. Few young people remain in the villages across the district, preferring to take their chances in South Africa working one menial contract job after the next, the Beitbridge on the border with South Africa makes their trek easier. In the past, the district generated some revenue from tourism, with numbers of tourists visiting the private game parks in the district. The district has many service and business centres of varying sizes, among these, Neshuro, Sarahuru, Sengejira, Maranda and Chaoma are noteworthy. However, some, like Neshuro, have continued to grow, with water, akin to other districts in Masvingo Province, the ZANU-PF party dominates politics. Ever since the independence, the constituency has been represented by a ZANU-PF party member in the parliament of Zimbabwe. Isaiah Shumba was the representative for Mwenezi, winning both the 2000 and 2005 elections on the ZANU-PF ticket, the district now sends two members to Zimbabwes new House of Assembly
36.
Basalt
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Basalt is a common extrusive igneous rock formed from the rapid cooling of basaltic lava exposed at or very near the surface of a planet or moon. Flood basalt describes the formation in a series of basalt flows. By definition, basalt is an igneous rock with generally 45-55% silica and less than 10% feldspathoid by volume. Basalt commonly features a very fine-grained or glassy matrix interspersed with visible mineral grains, the average density is 3.0 gm/cm3. Basalt is defined by its content and texture, and physical descriptions without mineralogical context may be unreliable in some circumstances. Basalt is usually grey to black in colour, but rapidly weathers to brown or rust-red due to oxidation of its mafic minerals into hematite, although usually characterized as dark, basaltic rocks exhibit a wide range of shading due to regional geochemical processes. Due to weathering or high concentrations of plagioclase, some basalts can be quite light-coloured and these phenocrysts usually are of olivine or a calcium-rich plagioclase, which have the highest melting temperatures of the typical minerals that can crystallize from the melt. Basalt with a texture is called vesicular basalt, when the bulk of the rock is mostly solid. Gabbro is often marketed commercially as black granite and these ultramafic volcanic rocks, with silica contents below 45% are usually classified as komatiites. Agricola applied basalt to the black rock of the Schloßberg at Stolpen. Tholeiitic basalt is relatively rich in silica and poor in sodium, included in this category are most basalts of the ocean floor, most large oceanic islands, and continental flood basalts such as the Columbia River Plateau. Basalt rocks are in some cases classified after their content in High-Ti and Low-Ti varieties. High-Ti and Low-Ti basalts have been distinguished in the Paraná and Etendeka traps and it has greater than 17% alumina and is intermediate in composition between tholeiite and alkali basalt, the relatively alumina-rich composition is based on rocks without phenocrysts of plagioclase. Alkali basalt is relatively poor in silica and rich in sodium and it is silica-undersaturated and may contain feldspathoids, alkali feldspar and phlogopite. Boninite is a form of basalt that is erupted generally in back-arc basins. Ocean island basalt Lunar basalt On Earth, most basalt magmas have formed by melting of the mantle. Basalt commonly erupts on Io, the third largest moon of Jupiter, and has formed on the Moon, Mars, Venus. The crustal portions of oceanic tectonic plates are composed predominantly of basalt, produced from upwelling mantle below, the mineralogy of basalt is characterized by a preponderance of calcic plagioclase feldspar and pyroxene
37.
Pegmatite
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A pegmatite is a holocrystalline, intrusive igneous rock composed of interlocking phaneritic crystals usually larger than 2.5 cm in size, such rocks are referred to as pegmatitic. The word pegmatite derives from Homeric Greek, πεγνυμι, which means “to bind together”, in reference to the crystals of quartz. Most pegmatites are composed of quartz, feldspar and mica, having a similar composition as granite. Crystal size is the most striking feature of pegmatites, with usually over 5 cm in size. Individual crystals over 10 metres long have been found, and many of the worlds largest crystals were found within pegmatites and these include, spodumene, microcline, beryl, and tourmaline. Similarly, crystal texture and form within pegmatitic rock may be taken to extreme size, perthite feldspar within a pegmatite often shows gigantic perthitic texture visible to the naked eye. The single feature that is diagnostic to all pegmatites is their large size crystal components, Pegmatite bodies are usually of minor size compared to typical intrusive rock bodies. Pegmatite body size is on the order of magnitude of one to a few hundred meters, compared to typical igneous rocks they are rather inhomogeneous and may show zones with different mineral assemblages. Crystal size and mineral assemblages are usually oriented parallel to the rock or even concentric for pegmatite lenses. Crystal growth rates in pegmatite must be slow to allow gigantic crystals to grow within the confines and pressures of the Earths crust. The mineralogy of a pegmatite is in most cases dominated by some form of feldspar, often with mica and usually with quartz and this is because of the difficulty in counting and sampling mineral grains in a rock which may have crystals from centimeters to meters across. Garnet, commonly almandine or spessartine, is a common mineral within pegmatites intruding mafic, pegmatites associated with granitic domes within the Archaean Yilgarn Craton intruding ultramafic and mafic rocks contain red, orange and brown almandine garnet. Syenite pegmatites are quartz depleted and contain large feldspathoid crystals instead, Pegmatite is difficult to sample representatively due to the large size of the constituent mineral crystals. Often, bulk samples of some 50–60 kg of rock must be crushed to obtain a meaningful, hence, pegmatite is often characterised by sampling the individual minerals which comprise the pegmatite, and comparisons are made according to mineral chemistry. Occasionally, enrichment in the trace elements will result in crystallisation of equally unusual and rare minerals such as beryl, tourmaline, columbite, tantalite, zinnwaldite. Pegmatites are the source of lithium either as spodumene, lithiophyllite or usually from lepidolite. The primary source for caesium is pollucite, a mineral from a zoned pegmatite, the majority of the worlds beryllium is sourced from non-gem quality beryl within pegmatite. Tantalum, niobium, rare-earth elements are sourced from a few pegmatites worldwide, bismuth, molybdenum and tin have been won from pegmatite, but this is not yet an important source of these metals
38.
Ultramafic rock
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Ultramafic are igneous and meta-igneous rocks with a very low silica content, generally >18% MgO, high FeO, low potassium, and are composed of usually greater than 90% mafic minerals. The Earths mantle is composed of ultramafic rocks, ultrabasic is a more inclusive term that includes igneous rocks with low silica content that may not be extremely enriched in Fe and Mg, such as carbonatites and ultrapotassic igneous rocks. Intrusive ultramafic rocks are found in large, layered ultramafic intrusions where differentiated rock types often occur in layers. Such cumulate rock types do not represent the chemistry of the magma from which they crystallized, the ultramafic intrusives include the dunites, peridotites and pyroxenites. Other rare varieties include troctolite which has a percentage of calcic plagioclase. Gabbro and norite often occur in the portions of the layered ultramafic sequences. Hornblendite and, rarely phlogopite, are also found, subvolcanic ultramafic rocks and dykes persist longer, but are also rare. Many of the lavas being produced on Io may be ultramafic, mercury also appears to have ultramafic volcanic rock. Examples include komatiite and picritic basalt, komatiites can be host to ore deposits of nickel. Ultrapotassic, ultramafic rocks such as lamprophyre, lamproite and kimberlite are known to have reached the surface of the Earth. Although no modern eruptions have been observed, analogues are preserved, most of these rocks occur as dikes, diatremes, lopoliths or laccoliths, and very rarely, intrusions. Most kimberlite and lampproite occurrences occur as volcanic and subvolcanic diatremes and maars, vents of Proterozoic lamproite, and Cenozoic lamproite are known, as are vents of Devonian lamprophyre. Kimberlite pipes in Canada, Russia and South Africa have incompletely preserved tephra and these are generally diatreme events and as such are not lava flows although tephra and ash deposits are partially preserved. These represent low-volume volatile melts and attain their ultramafic chemistry via a different process to typical ultramafic rocks, metamorphism of ultramafic rocks in the presence of water and/or carbon dioxide results in two main classes of metamorphic ultramafic rock, talc carbonate and serpentinite. When such metamorphic fluids have less than 10% molar proportion of CO2, reactions favor serpentinisation, the majority of ultramafic rocks are exposed in orogenic belts, and predominate in Archaean and Proterozoic terranes. Ultramafic magmas in the Phanerozoic are rarer, and there are very few recognised true ultramafic lavas in the Phanerozoic, many surface exposures of ultramafic rocks occur in ophiolite complexes where deep mantle-derived rocks have been obducted onto continental crust along and above subduction zones. Serpentine soil is a rich, calcium, potassium and phosphorus poor soil that develops on the regolith derived from ultramafic rocks. Ultramafic rocks also contain elevated amounts of chromium and nickel which may be toxic to plants, as a result, a distinctive type of vegetation develops on these soils
39.
Analcime
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Analcime or analcite is a white, gray, or colorless tectosilicate mineral. Analcime consists of hydrated sodium aluminium silicate in cubic crystalline form, minor amounts of potassium and calcium substitute for sodium. A silver-bearing synthetic variety also exists, analcime is usually classified as a zeolite mineral, but structurally and chemically it is more similar to the feldspathoids. Analcime occurs as a mineral in analcime basalt and other alkaline igneous rocks. It also occurs as cavity and vesicle fillings associated with prehnite, calcite, list of minerals Hurlbut, Cornelius S. Klein, Cornelis,1985, Manual of Mineralogy, 20th ed. ISBN 0-471-80580-7 Mineral Galleries Mindat. org Webmineral. com structure type ANA
40.
Diopside
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Diopside is a monoclinic pyroxene mineral with composition MgCaSi2O6. It forms complete solid solution series with hedenbergite and augite, and partial solid solutions with orthopyroxene and it forms variably colored, but typically dull green crystals in the monoclinic prismatic class. It has two distinct prismatic cleavages at 87 and 93° typical of the pyroxene series. It has a Mohs hardness of six, a Vickers hardness of 7.7 GPa at a load of 0.98 N, and a specific gravity of 3.25 to 3.55. It is transparent to translucent with indices of refraction of nα=1. 663–1.699, nβ=1. 671–1.705, the optic angle is 58° to 63°. Diopside is found in igneous rocks, and diopside-rich augite is common in mafic rocks, such as olivine basalt. Diopside is also found in a variety of rocks, such as in contact metamorphosed skarns developed from high silica dolomites. It is an important mineral in the Earths mantle and is common in peridotite xenoliths erupted in kimberlite, some vermiculite deposits, most notably those in Libby, Montana, are contaminated with chrysotile that formed from diopside. At relatively high temperatures, there is a miscibility gap between diopside and pigeonite, and at lower temperatures, between diopside and orthopyroxene. Chrome diopside is a constituent of peridotite xenoliths, and dispersed grains are found near kimberlite pipes. Occurrences are reported in Canada, South Africa, Russia, Brazil, much chromian diopside from the Green River Basin localities and several of the State Line Kimberlites have been gem in character. Gemstone quality diopside is found in two forms, the black star diopside and the chrome diopside, at 5. 5–6.5 on the Mohs scale, chrome diopside is relatively soft to scratch. Violane is a variety of diopside, violet to light blue in color. Diopside derives its name from the Greek dis, twice, and òpsè, Diopside was discovered and first described about 1800, by Brazilian naturalist Jose Bonifacio de Andrada e Silva. Diopside based ceramics and glass-ceramics have potential applications in various technological areas, a diopside based glass-ceramic named silceram was produced by scientists from Imperial College, UK during the 1980s from blast furnace slag and other waste products. The as produced glass-ceramic is a structural material. Similarly, diopside based ceramics and glass-ceramics have potential applications in the field of biomaterials, nuclear waste immobilization, S. Carter, C. B. Ponton, R. D. Rawlings, P. S. Rogers, Microstructure, chemistry, elastic properties and internal-friction of silceram glass-ceramics, T. Nonami, S. Tsutsumi, Study of diopside ceramics for biomaterials, Journal of Materials Science, Materials in Medicine 10 475-479
41.
Phlogopite
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Phlogopite is a yellow, greenish, or reddish-brown member of the mica family of phyllosilicates. It is also known as magnesium mica, phlogopite is the magnesium endmember of the biotite solid solution series, with the chemical formula KMg3AlSi3O102. Iron substitutes for magnesium in variable amounts leading to the more common biotite with higher iron content, for physical and optical identification, it shares most of the characteristic properties of biotite. Phlogopite is an important and relatively common end-member composition of biotite, several igneous associations are noted, high-alumina basalts, ultrapotassic igneous rocks, and ultramafic rocks. The basaltic occurrence of phlogopite is in association with picrite basalts, phlogopite is stable in basaltic compositions at high pressures and is often present as partially resorbed phenocrysts or an accessory phase in basalts generated at depth. Phlogopite in this association is a primary igneous mineral present because of the depth of melting, phlogopite is often found in association with ultramafic intrusions as a secondary alteration phase within metasomatic margins of large layered intrusions. In some cases the phlogopite is considered to be produced by autogenic alteration during cooling, in other instances, metasomatism has resulted in phlogopite formation within large volumes, as in the ultramafic massif at Finero, Italy, within the Ivrea zone. Phlogopite is encountered as a primary igneous phenocryst within lamproites and lamprophyres, the largest documented single crystal of phlogopite was found in Lacey mine, Ontario, Canada, it measured 10x4. 3x4.3 m3 and weighed about 330 tonnes. Similar-sized crystals were found in Karelia, Russia. Howie, and J. Zussman, Rock-forming minerals, v.3, sheet silicates, p. 42–54 Spencer, Leonard James
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Pseudobrookite
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Pseudobrookite is an iron titanium oxide mineral with formula, Fe2TiO5 or 2O5. Pseudobrookite was first described in 1878 for an occurrence in Uroi Hill, Simeria, Hunedoara County, the name is from Greek ψευδής, for false, and brookite because of its misleading similar appearance to brookite. Pseudobrookite forms as pneumatolytic deposition and alteration within titanium-rich volcanic rocks such as andesite, rhyolite or basalt and it may be associated with xenoliths contained in the volcanics. It also commonly occurs in lithophysae and it occurs associated with hematite, magnetite, bixbyite, ilmenite, enstatite-ferrosilite, tridymite, quartz, sanidine, topaz, spessartine, beryl, mica, cassiterite and apatite
