1.
Leucocratic
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In geology, felsic refers to igneous rocks that are relatively rich in elements that form feldspar and quartz. It is contrasted with mafic rocks, which are richer in magnesium. It refers to those rocks rich in minerals, magma, and rocks which are enriched in the lighter elements such as silicon, oxygen, aluminium, sodium. They are usually light in color and have specific gravities less than 3, the most common felsic rock is granite. Common felsic minerals include quartz, muscovite, orthoclase, and the sodium-rich plagioclase feldspars, in terms of chemistry, felsic minerals and rocks are at the other end of the elemental spectrum from the mafic minerals and rocks. In modern usage, the acid rock, although sometimes used as a synonym, refers to a high-silica-content volcanic rock. The term was used broadly in older geologic literature. It is considered archaic now, as the acidic and basic rock were based on an incorrect idea, dating from the 19th century. The term felsic combines the words feldspar and silica, in order for a rock to be classified as felsic, it generally needs to contain more than 75% felsic minerals, namely quartz, orthoclase and plagioclase. Rocks with greater than 90% felsic minerals can also be called leucocratic, the chemical name of a felsic rock is given according to the TAS classification of Le Maitre. However, this applies to volcanic rocks. If the rock is analyzed and found to be felsic but is metamorphic and has no definite volcanic protolith, there are examples known of highly sheared granites which can be mistaken for rhyolites. For phaneritic felsic rocks, the QAPF diagram should be used, the rock texture thus determines the basic name of a felsic rock. QAPF diagram List of minerals List of rock types Le Maitre, igneous Rocks, A Classification and Glossary of Terms 2nd edition, Cambridge
2.
Nepheline
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Nepheline crystals are rare and belong to the hexagonal system, usually having the form of a short, six-sided prism terminated by the basal plane. It is found in compact, granular aggregates, and can be white, yellow, gray, green, the hardness is 5.5 -6, and the specific gravity 2.56 -2.66. It is often translucent with a greasy luster, an important determinative character of nepheline is the ease with which it is decomposed by hydrochloric acid, with separation of gelatinous silica and cubes of salt. For this reason, a crystal of nepheline becomes cloudy when immersed in acid. It has therefore been suggested that the formula, AlSiO4. The mineral is one liable to alteration, and in the laboratory various substitution products of nepheline have been prepared. In nature it is altered to zeolites, sodalite, kaolin. Two varieties of nepheline are distinguished, differing in their appearance and in their mode of occurrence, being analogous in these respects to sanidine. Glassy nepheline has the form of small, colorless, transparent crystals and it is characteristic of the later volcanic rocks rich in alkalis, such as phonolite, nepheline-basalt, leucite basalt, etc. and also of certain dike-rocks, such as tinguaite. The best crystals occur with mica, sanidine, garnet, etc. in the cavities of the ejected blocks of Monte Somma. It forms a constituent of certain alkaline plutonic rocks of the nepheline syenite series. The color and greasy luster of elaeolite are due to the presence of numerous microscopic enclosures of other minerals and this article incorporates text from a publication now in the public domain, Leonard James Spencer. Media related to Nepheline at Wikimedia Commons
3.
Sweden
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Sweden, officially the Kingdom of Sweden, is a Scandinavian country in Northern Europe. It borders Norway to the west and Finland to the east, at 450,295 square kilometres, Sweden is the third-largest country in the European Union by area, with a total population of 10.0 million. Sweden consequently has a low density of 22 inhabitants per square kilometre. Approximately 85% of the lives in urban areas. Germanic peoples have inhabited Sweden since prehistoric times, emerging into history as the Geats/Götar and Swedes/Svear, Southern Sweden is predominantly agricultural, while the north is heavily forested. Sweden is part of the area of Fennoscandia. The climate is in very mild for its northerly latitude due to significant maritime influence. Today, Sweden is a monarchy and parliamentary democracy, with a monarch as head of state. The capital city is Stockholm, which is also the most populous city in the country, legislative power is vested in the 349-member unicameral Riksdag. Executive power is exercised by the government chaired by the prime minister, Sweden is a unitary state, currently divided into 21 counties and 290 municipalities. Sweden emerged as an independent and unified country during the Middle Ages, in the 17th century, it expanded its territories to form the Swedish Empire, which became one of the great powers of Europe until the early 18th century. Swedish territories outside the Scandinavian Peninsula were gradually lost during the 18th and 19th centuries, the last war in which Sweden was directly involved was in 1814, when Norway was militarily forced into personal union. Since then, Sweden has been at peace, maintaining a policy of neutrality in foreign affairs. The union with Norway was peacefully dissolved in 1905, leading to Swedens current borders, though Sweden was formally neutral through both world wars, Sweden engaged in humanitarian efforts, such as taking in refugees from German-occupied Europe. After the end of the Cold War, Sweden joined the European Union on 1 January 1995 and it is also a member of the United Nations, the Nordic Council, Council of Europe, the World Trade Organization and the Organisation for Economic Co-operation and Development. Sweden maintains a Nordic social welfare system that provides health care. The modern name Sweden is derived through back-formation from Old English Swēoþēod and this word is derived from Sweon/Sweonas. The Swedish name Sverige literally means Realm of the Swedes, excluding the Geats in Götaland, the etymology of Swedes, and thus Sweden, is generally not agreed upon but may derive from Proto-Germanic Swihoniz meaning ones own, referring to ones own Germanic tribe
4.
Intrusive rock
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Intrusive rock is formed when magma crystallizes and solidifies underground to form intrusions, for example plutons, batholiths, dikes, sills, laccoliths, and volcanic necks. Intrusive rock forms within Earths crust from the crystallization of magma, magma slowly pushes up from deep within the earth into any cracks or spaces it can find, sometimes pushing existing country rock out of the way, a process that can take millions of years. As the magma slowly cools into a solid, the different parts of the magma crystallize into rocks, many mountain ranges, such as the Sierra Nevada in California, are formed mostly from large granite intrusions, see Sierra Nevada Batholith. Intrusions are one of the two ways igneous rock can form, the other is extrusive rock, that is, an eruption or similar event. Technically speaking, an intrusion is any formation of igneous rock, rock formed from magma that cools. In contrast, an extrusion consists of rock, rock formed above the surface of the crust. Large bodies of magma that solidify underground before they reach the surface of the crust are called plutons, plutonic rocks form 7% of the Earths current land surface. Coarse-grained intrusive igneous rocks form at depth within the earth are called abyssal while those that form near the surface are called subvolcanic or hypabyssal. The term intrusive suite seems near synonymous, there is, however, a modest difference, An intrusive suite is a group of plutons related in time and space. Intrusions vary widely, from mountain-range-sized batholiths to thin veinlike fracture fillings of aplite or pegmatite, when exposed by erosion, such batholiths may occupy large areas. A well-known example of an intrusion is Devils Tower, another is Shiprock, New Mexico, USA. Be the pluton is large, it may be called a batholith or a stock, Intrusive rocks are characterized by large crystal sizes, and as the individual crystals are visible, the rock is called phaneritic. This is as the magma cools underground, and while cooling may be fast or slow, cooling is slower than on the surface, if it runs parallel to rock layers, it is called a sill. If an intrusion makes rocks above rise to form a dome, as heat dissipation is slow, and as the rock is under pressure, crystals form, and no vitreous rapidly chilled matter is present. The intrusions did not flow while solidifying, hence do not show lines, contained gases could not escape through the thick strata, thus form cavities, which can often be observed. Because their crystals are of the rough equal size, these rocks are said to be equigranular, there is typically no distinction between a first generation of large well-shaped crystals and a fine-grained ground-mass. Earlier crystals originated at a time when most of the rock was still liquid and are more or less perfect, later crystals are less regular in shape because they were compelled to occupy the spaces left between the already-formed crystals. The former case is said to be idiomorphic, the latter is xenomorphic, there are also many other characteristics that serve to distinguish the members of these two groups
5.
Igneous rock
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Igneous rock, or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava, the magma can be derived from partial melts of existing rocks in either a planets mantle or crust. Typically, the melting is caused by one or more of three processes, an increase in temperature, a decrease in pressure, or a change in composition, solidification into rock occurs either below the surface as intrusive rocks or on the surface as extrusive rocks. Igneous rock may form with crystallization to form granular, crystalline rocks, Igneous and metamorphic rocks make up 90–95% of the top 16 km of the Earths crust by volume. Igneous rocks form about 15% of the Earths current land surface, most of the Earths oceanic crust is made of igneous rock. In terms of modes of occurrence, igneous rocks can be either intrusive or extrusive, the mineral grains in such rocks can generally be identified with the naked eye. Intrusive rocks can also be classified according to the shape and size of the intrusive body, typical intrusive formations are batholiths, stocks, laccoliths, sills and dikes. When the magma solidifies within the earths crust, it cools slowly forming coarse textured rocks, such as granite, gabbro, the central cores of major mountain ranges consist of intrusive igneous rocks, usually granite. When exposed by erosion, these cores may occupy huge areas of the Earths surface, intrusive igneous rocks that form at depth within the crust are termed plutonic rocks and are usually coarse-grained. Intrusive igneous rocks that form near the surface are termed subvolcanic or hypabyssal rocks, hypabyssal rocks are less common than plutonic or volcanic rocks and often form dikes, sills, laccoliths, lopoliths, or phacoliths. Extrusive igneous rocks, also known as rocks, are formed at the crusts surface as a result of the partial melting of rocks within the mantle. Extrusive igneous rocks cool and solidify quicker than intrusive igneous rocks and they are formed by the cooling of molten magma on the earths surface. The magma, which is brought to the surface through fissures or volcanic eruptions, hence such rocks are smooth, crystalline and fine-grained. Basalt is an extrusive igneous rock and forms lava flows, lava sheets. Some kinds of basalt solidify to form long polygonal columns, the Giants Causeway in Antrim, Northern Ireland is an example. The molten rock, with or without suspended crystals and gas bubbles, is called magma and it rises because it is less dense than the rock from which it was created. When magma reaches the surface from beneath water or air, it is called lava, eruptions of volcanoes into air are termed subaerial, whereas those occurring underneath the ocean are termed submarine. Black smokers and mid-ocean ridge basalt are examples of volcanic activity
6.
Granite
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Granite is a common type of felsic intrusive igneous rock that is granular and phaneritic in texture. Granites can be white, pink, or gray in color. The word granite comes from the Latin granum, a grain, in reference to the structure of such a holocrystalline rock. By definition, granite is a rock with at least 20% quartz. The term granitic means granite-like and is applied to granite and a group of igneous rocks with similar textures and slight variations in composition. Occasionally some individual crystals are larger than the groundmass, in case the texture is known as porphyritic. A granitic rock with a texture is known as a granite porphyry. Granitoid is a general, descriptive field term for lighter-colored, coarse-grained igneous rocks, petrographic examination is required for identification of specific types of granitoids. The extrusive igneous rock equivalent of granite is rhyolite, Granite is nearly always massive, hard and tough, and therefore it has gained widespread use throughout human history, and more recently as a construction stone. The average density of granite is between 2.65 and 2.75 g/cm3, its compressive strength usually lies above 200 MPa, and its viscosity near STP is 3–6 •1019 Pa·s. The melting temperature of dry granite at ambient pressure is 1215–1260 °C, it is reduced in the presence of water. Granite has poor primary permeability, but strong secondary permeability, true granite according to modern petrologic convention contains both plagioclase and alkali feldspars. When a granitoid is devoid or nearly devoid of plagioclase, the rock is referred to as alkali feldspar granite, when a granitoid contains less than 10% orthoclase, it is called tonalite, pyroxene and amphibole are common in tonalite. A granite containing both muscovite and biotite micas is called a binary or two-mica granite, two-mica granites are typically high in potassium and low in plagioclase, and are usually S-type granites or A-type granites. A worldwide average of the composition of granite, by weight percent, based on 2485 analyses. Much of it was intruded during the Precambrian age, it is the most abundant basement rock that underlies the relatively thin veneer of the continents. Outcrops of granite tend to form tors and rounded massifs, granites sometimes occur in circular depressions surrounded by a range of hills, formed by the metamorphic aureole or hornfels. Granite often occurs as small, less than 100 km² stock masses
7.
Quartz
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Quartz is the second most abundant mineral in Earths continental crust, behind feldspar. There are many different varieties of quartz, several of which are semi-precious gemstones, since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Eurasia. The word quartz is derived from the German word Quarz and its Middle High German ancestor twarc, the Ancient Greeks referred to quartz as κρύσταλλος derived from the Ancient Greek κρύος meaning icy cold, because some philosophers apparently believed the mineral to be a form of supercooled ice. Today, the rock crystal is sometimes used as an alternative name for the purest form of quartz. Quartz belongs to the crystal system. The ideal crystal shape is a six-sided prism terminating with six-sided pyramids at each end, well-formed crystals typically form in a bed that has unconstrained growth into a void, usually the crystals are attached at the other end to a matrix and only one termination pyramid is present. However, doubly terminated crystals do occur where they develop freely without attachment, a quartz geode is such a situation where the void is approximately spherical in shape, lined with a bed of crystals pointing inward. α-quartz crystallizes in the crystal system, space group P3121 and P3221 respectively. β-quartz belongs to the system, space group P6222 and P6422. These space groups are truly chiral, both α-quartz and β-quartz are examples of chiral crystal structures composed of achiral building blocks. The transformation between α- and β-quartz only involves a comparatively minor rotation of the tetrahedra with respect to one another, although many of the varietal names historically arose from the color of the mineral, current scientific naming schemes refer primarily to the microstructure of the mineral. Color is an identifier for the cryptocrystalline minerals, although it is a primary identifier for the macrocrystalline varieties. Pure quartz, traditionally called rock crystal or clear quartz, is colorless and transparent or translucent, common colored varieties include citrine, rose quartz, amethyst, smoky quartz, milky quartz, and others. The most important distinction between types of quartz is that of macrocrystalline and the microcrystalline or cryptocrystalline varieties, the cryptocrystalline varieties are either translucent or mostly opaque, while the transparent varieties tend to be macrocrystalline. Chalcedony is a form of silica consisting of fine intergrowths of both quartz, and its monoclinic polymorph moganite. Other opaque gemstone varieties of quartz, or mixed rocks including quartz, often including contrasting bands or patterns of color, are agate, carnelian or sard, onyx, heliotrope, amethyst is a form of quartz that ranges from a bright to dark or dull purple color. The worlds largest deposits of amethysts can be found in Brazil, Mexico, Uruguay, Russia, France, Namibia, sometimes amethyst and citrine are found growing in the same crystal. It is then referred to as ametrine, an amethyst is formed when there is iron in the area where it was formed
8.
Mafic
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Mafic is an adjective describing a silicate mineral or igneous rock that is rich in magnesium and iron, and is thus a portmanteau of magnesium and ferric. Most mafic minerals are dark in color, and common rock-forming mafic minerals include olivine, pyroxene, amphibole, common mafic rocks include basalt, dolerite and gabbro. Mafic rocks often also contain calcium-rich varieties of plagioclase feldspar, chemically, mafic rocks are on the other side of the rock spectrum from the felsic rocks. The term roughly corresponds to the basic rock class. Mafic lava, before cooling, has a low viscosity, in comparison to felsic lava, water and other volatiles can more easily and gradually escape from mafic lava. As a result, eruptions of volcanoes made of mafic lavas are less violent than felsic-lava eruptions. Most mafic-lava volcanoes are shield volcanoes, like those in Hawaii, QAPF diagram List of minerals List of rock types
9.
Felsic
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In geology, felsic refers to igneous rocks that are relatively rich in elements that form feldspar and quartz. It is contrasted with mafic rocks, which are richer in magnesium. It refers to those rocks rich in minerals, magma, and rocks which are enriched in the lighter elements such as silicon, oxygen, aluminium, sodium. They are usually light in color and have specific gravities less than 3, the most common felsic rock is granite. Common felsic minerals include quartz, muscovite, orthoclase, and the sodium-rich plagioclase feldspars, in terms of chemistry, felsic minerals and rocks are at the other end of the elemental spectrum from the mafic minerals and rocks. In modern usage, the acid rock, although sometimes used as a synonym, refers to a high-silica-content volcanic rock. The term was used broadly in older geologic literature. It is considered archaic now, as the acidic and basic rock were based on an incorrect idea, dating from the 19th century. The term felsic combines the words feldspar and silica, in order for a rock to be classified as felsic, it generally needs to contain more than 75% felsic minerals, namely quartz, orthoclase and plagioclase. Rocks with greater than 90% felsic minerals can also be called leucocratic, the chemical name of a felsic rock is given according to the TAS classification of Le Maitre. However, this applies to volcanic rocks. If the rock is analyzed and found to be felsic but is metamorphic and has no definite volcanic protolith, there are examples known of highly sheared granites which can be mistaken for rhyolites. For phaneritic felsic rocks, the QAPF diagram should be used, the rock texture thus determines the basic name of a felsic rock. QAPF diagram List of minerals List of rock types Le Maitre, igneous Rocks, A Classification and Glossary of Terms 2nd edition, Cambridge
10.
Trachyte
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Trachyte is an igneous volcanic rock with an aphanitic to porphyritic texture. It is the equivalent of syenite. The mineral assemblage consists of essential alkali feldspar, relatively minor plagioclase, biotite, clinopyroxene and olivine are common accessory minerals. Chemically, trachyte contains 60 to 65% silica content, less SiO2 than rhyolite and these chemical differences are consistent with the position of trachyte in the TAS classification, and they account for the feldspar-rich mineralogy of the rock type. Trachytes usually consist mainly of sanidine feldspar, very often they have minute irregular steam cavities which make the broken surfaces of specimens of these rocks rough and irregular, and from this character they have derived their name. The trachytes are often described as being the equivalents of the plutonic syenites. Rhomb porphyry is an example with usually large porphyritic rhomb shaped phenocrysts embedded in a very fine-grained matrix, quartz is typically rare in trachyte, but tridymite is by no means uncommon. They often cover the surfaces of the larger feldspars or line the cavities of the rock. In the older trachytes, secondary quartz is not rare, of the mafic minerals present, augite is the most common. It is usually of pale color, and its small crystals are often very perfect in form. Olivine is unusual, though found in some trachytes, like those of the Arso in Ischia, basic varieties of plagioclase, such as labradorite, are known also as phenocrysts in some Italian trachytes. Dark brown varieties of augite and rhombic pyroxene have been observed but are not common, apatite, zircon and magnetite are practically always present as accessory minerals. Trachytes, being rich in potassium feldspar, necessarily contain considerable amounts of alkali. Occasionally minerals of the group, such as nepheline, sodalite and leucite, occur. In many trachytes, however, the phenocrysts are few and small, the ferromagnesian minerals rarely occur in large crystals, and are usually not conspicuous in hand specimens of these rocks. Sometimes granular augite or spongy riebeckite occurs in the groundmass, trachytes are well represented among the Cenozoic volcanic rocks of Europe. In the neighborhood of Rome, Naples and the island of Ischia trachytic lavas, trachytes are also found on the island of Pantelleria. In the United States, trachytes crop out extensively in the Davis Mountains, Chisos Mountains, in England there are Permian trachytes in the Exeter district, and Carboniferous trachytes are found in many parts of the central valley of Scotland
11.
Feldspar
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Feldspars are a group of rock-forming tectosilicate minerals that make up about 40% of the Earths continental crust. Feldspars crystallize from magma as veins in both intrusive and extrusive rocks and are also present in many types of metamorphic rock. Rock formed almost entirely of plagioclase feldspar is known as anorthosite. Feldspars are also found in types of sedimentary rocks. The name feldspar derives from the German Feldspat, a compound of the words Feld, field, and Spat, the change from Spat to -spar was influenced by the English word spar, a synonym for mineral. Feldspathic refers to materials that contain feldspar, the alternate spelling, felspar, has largely fallen out of use. This group of minerals consists of tectosilicates, solid solutions between albite and anorthite are called plagioclase, or more properly plagioclase feldspar. Only limited solid solution occurs between K-feldspar and anorthite, and in the two solid solutions, immiscibility occurs at temperatures common in the crust of the earth. Albite is considered both a plagioclase and alkali feldspar, the alkali feldspars are as follows, orthoclase —KAlSi3O8 sanidine —AlSi3O8 microcline —KAlSi3O8 anorthoclase —AlSi3O8 Sanidine is stable at the highest temperatures, and microcline at the lowest. Perthite is a texture in alkali feldspar, due to exsolution of contrasting alkali feldspar compositions during cooling of an intermediate composition. The perthitic textures in the alkali feldspars of many granites can be seen with the naked eye, microperthitic textures in crystals are visible using a light microscope, whereas cryptoperthitic textures can be seen only with an electron microscope. Barium feldspars are also considered alkali feldspars, barium feldspars form as the result of the substitution of barium for potassium in the mineral structure. The barium feldspars are monoclinic and include the following, celsian—BaAl2Si2O8 hyalophane—4O8 The plagioclase feldspars are triclinic, the immiscibility gaps in the plagioclase solid solutions are complex compared to the gap in the alkali feldspars. The play of colours visible in some feldspar of labradorite composition is due to very fine-grained exsolution lamellae, chemical weathering of feldspars results in the formation of clay minerals. About 20 million tonnes of feldspar were produced in 2010, mostly by three countries, Italy, Turkey, and China, Feldspar is a common raw material used in glassmaking, ceramics, and to some extent as a filler and extender in paint, plastics, and rubber. In glassmaking, alumina from feldspar improves product hardness, durability, in ceramics, the alkalis in feldspar act as a flux, lowering the melting temperature of a mixture. Fluxes melt at a stage in the firing process, forming a glassy matrix that bonds the other components of the system together. In the US, about 66% of feldspar is consumed in glassmaking, including glass containers, ceramics and other uses, such as fillers, accounted for the remainder
12.
Alkaline
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Alkalinity is the name given to the quantitative capacity of an aqueous solution to neutralize an acid. Measuring alkalinity is important in determining a streams ability to neutralize acidic pollution from rainfall or wastewater and it is one of the best measures of the sensitivity of the stream to acid inputs. There can be changes in the alkalinity of streams and rivers in response to human disturbances. Alkalinity is related to the pH of a solution, but measures a different property, roughly, the alkalinity of a solution is a measure of how strong the bases are in a solution, whereas the pH measures the amount of chemical bases. A good example is a solution, which can have many available bases despite having only a moderate pH level. Alkalinity roughly refers to the amount of bases in a solution that can be converted to uncharged species by a strong acid. The cited author, James Drever, provides an equation expressed in terms of molar equivalents, which means the number of moles of each ion type multiplied by the charge of the ion. For example,1 mole of HCO31− in solution represents 1 molar equivalent, the total charge of a solution always equals zero. On the left-hand side of the equation is the sum of conservative cations minus the sum of conservative anions, balancing this on the right side is the sum of the anions that could be neutralized by added H+ ions minus H+ ions already present, as indicated by the pH. This right side term is called total alkalinity and it is, quoting Drever, formally defined as the equivalent sum of the bases that are titratable with strong acid. The listing of ions shown on the right in Drever was mHCO3− + 2mCO32− + mB4− + mH34− + mHS− + morganic anions + mOH− - mH+, total alkalinity is measured by adding a strong acid until all the anions listed above are converted to uncharged species. The total alkalinity is not affected by temperature, pressure, or pH, though the values of individual constituents are, Drever further notes that in most natural waters, all ions except HCO3− and CO3−2 have low concentrations. Thus carbonate alkalinity, which is equal to mHCO3− + 2mCO3−2 is also equal to the total alkalinity. Alkalinity or AT measures the ability of a solution to neutralize acids to the point of carbonate or bicarbonate. The alkalinity is equal to the sum of the bases in solution. Other common natural components that can contribute to alkalinity include borate, hydroxide, phosphate, silicate, dissolved ammonia, the bases of some organic acids. Solutions produced in a laboratory may contain a virtually limitless number of bases that contribute to alkalinity, Alkalinity is usually given in the unit mEq/L. Commercially, as in the pool industry, alkalinity might also be given in parts per million of equivalent calcium carbonate
13.
Orthoclase
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Orthoclase, or orthoclase feldspar, is an important tectosilicate mineral which forms igneous rock. The name is from the Ancient Greek for straight fracture, because its two planes are at right angles to each other. It is a type of potassium feldspar, also known as K-feldspar, the gem known as moonstone is largely composed of orthoclase. Orthoclase is a constituent of most granites and other felsic igneous rocks and often forms huge crystals. Typically, the pure potassium endmember of orthoclase forms a solution with albite. While slowly cooling within the earth, sodium-rich albite lamellae form by exsolution, the resulting intergrowth of the two feldspars is called perthite. The higher-temperature polymorph of KAlSi3O8 is sanidine, sanidine is common in rapidly cooled volcanic rocks such as obsidian and felsic pyroclastic rocks, and is notably found in trachytes of the Drachenfels, Germany. The lower-temperature polymorph of KAlSi3O8 is microcline, adularia is a low temperature form of either microcline or orthoclase originally reported from the low temperature hydrothermal deposits in the Adula Alps of Switzerland. It was first described by Ermenegildo Pini in 1781, the optical effect of adularescence in moonstone is typically due to adularia. The largest documented crystal of orthoclase was found in Ural mountains. It measured ~10×10×0.4 m and weighed ~100 tons, together with the other potassium feldspars, orthoclase is a common raw material for the manufacture of some glasses and some ceramics such as porcelain, and as a constituent of scouring powder. Some intergrowths of orthoclase and albite have an attractive pale luster and are called moonstone when used in jewellery, most moonstones are translucent and white, although grey and peach-colored varieties also occur. In gemology, their luster is called adularescence and is described as creamy or silvery white with a billowy quality. It is the gem of Florida. Orthoclase is one of the ten defining minerals of the Mohs scale of mineral hardness, nASAs Curiosity Rover discovery of high levels of orthoclase in Martian sandstones suggested that some Martian rocks may have experienced complex geological processing, such as repeated melting
14.
Plagioclase
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Plagioclase is a series of tectosilicate minerals within the feldspar group. Rather than referring to a mineral with a specific chemical composition, plagioclase is a continuous solid solution series. This was first shown by the German mineralogist Johann Friedrich Christian Hessel in 1826, the series ranges from albite to anorthite endmembers, where sodium and calcium atoms can substitute for each other in the minerals crystal lattice structure. Plagioclase in hand samples is often identified by its polysynthetic crystal twinning or record-groove effect, plagioclase is a major constituent mineral in the Earths crust, and is consequently an important diagnostic tool in petrology for identifying the composition, origin and evolution of igneous rocks. Plagioclase is also a constituent of rock in the highlands of the Earths moon. Analysis of thermal emission spectra from the surface of Mars suggests that plagioclase is the most abundant mineral in the crust of Mars, the extinction angle is an optical characteristic and varies with the albite fraction. There are several named plagioclase feldspars that fall between albite and anorthite in the series, the following table shows their compositions in terms of constituent anorthite and albite percentages. Anorthite was named by Gustav Rose in 1823 from the Ancient Greek meaning oblique, anorthite is a comparatively rare mineral but occurs in the basic plutonic rocks of some orogenic calc-alkaline suites. Albite is named from the Latin albus, in reference to its pure white color. It is a common and important rock-making mineral associated with the more acid rock types and in pegmatite dikes, often with rarer minerals like tourmaline. The intermediate members of the group are very similar to each other. Bytownite, named after the name for Ottawa, Canada, is a rare mineral occasionally found in more basic rocks. Labradorite is the characteristic feldspar of the basic rock types such as diorite, gabbro, andesite. Labradorite frequently shows an iridescent display of colors due to light refracting within the lamellae of the crystal and it is named after Labrador, where it is a constituent of the intrusive igneous rock anorthosite which is composed almost entirely of plagioclase. A variety of known as spectrolite is found in Finland. Andesine is a mineral of rocks such as diorite which contain a moderate amount of silica. Oligoclase is common in granite, syenite, diorite, and gneiss and it is a frequent associate of orthoclase. The name oligoclase is derived from the Greek for little and fracture, sunstone is mainly oligoclase with flakes of hematite
15.
Perthite
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Perthite is used to describe an intergrowth of two feldspars, a host grain of potassium-rich alkali feldspar includes exsolved lamellae or irregular intergrowths of sodic alkali feldspar. Typically the host grain is orthoclase or microcline, and the lamellae are albite, if sodic feldspar is the dominant phase, the result is an antiperthite. The intergrowth forms by exsolution due to cooling of a grain of alkali feldspar with an intermediate between K-feldspar and albite. If an alkali feldspar grain with an intermediate composition cools slowly enough, K-rich, in the presence of water, the process occurs quickly. When megascopically developed, the texture may consist of distinct pink, the intergrowths in perthite have a great variety of shapes. If cooling is slow, the alkali feldspar may exsolve to form separate grains with near-endmember albite. The largest documented crystal of perthite was found in Hugo Mine in South Dakota. The gem varieties of feldspar, amazonite and moonstone are variant colored perthites
16.
Hornblende
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Hornblende is a complex inosilicate series of minerals. It is not a mineral in its own right, but the name is used as a general or field term. Hornblende is a mixture of three molecules, a calcium-iron-magnesium silicate, an aluminium-iron-magnesium silicate, and an iron-magnesium silicate. The general formula can be given as 2–358O222, some metals vary in their occurrence and magnitude, Manganese and titanium are often present. Sodium and potassium are present and fluorine often substitutes for the hydroxyl in the crystalline structure. Hornblende has a hardness of 5–6, a gravity of 2. 9–3.4 and is typically an opaque green. Its cleavage angles are at 56 and 124 degrees and it is most often confused with various pyroxene minerals and biotite mica, which are black and can be found in granite and in charnockite. Hornblende is a constituent of many igneous and metamorphic rocks such as granite, syenite, diorite, gabbro, basalt, andesite, gneiss. It is the mineral of amphibolites. Very dark brown to black hornblendes that contain titanium are ordinarily called basaltic hornblende, from the fact that they are usually a constituent of basalt, hornblende alters easily to chlorite and epidote. A rare variety of hornblende contains less than 5% of iron oxide, is gray to white in color, and named edenite, from its locality in Edenville, Orange County, New York. List of minerals Hurlbut, Cornelius S. Klein, Cornelis,1985, Manual of Mineralogy, 20th ed. John Wiley and Sons, New York, p 416-7, ISBN 0-471-80580-7 Scandinavian mineral gallery retrieved 06/21/05
17.
Amphibole
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Amphiboles can be green, black, colorless, white, yellow, blue, or brown. The International Mineralogical Association currently classifies amphiboles as a mineral supergroup, amphiboles crystallize into two crystal systems, monoclinic and orthorhombic. In chemical composition and general characteristics they are similar to the pyroxenes, the chief differences from pyroxenes are that amphiboles contain essential hydroxyl or halogen and the basic structure is a double chain of tetrahedra. Most apparent, in specimens, is that amphiboles form oblique cleavage planes. Amphiboles are also less dense than the corresponding pyroxenes. In optical characteristics, many amphiboles are distinguished by their stronger pleochroism, amphiboles are the primary constituent of amphibolites. Amphiboles are minerals of either igneous or metamorphic origin, in the former case occurring as constituents of rocks, such as granite, diorite, andesite. Calcium is sometimes a constituent of naturally occurring amphiboles and those of metamorphic origin include examples such as those developed in limestones by contact metamorphism and those formed by the alteration of other ferromagnesian minerals. Pseudomorphs of amphibole after pyroxene are known as uralite, the name amphibole was used by René Just Haüy to include tremolite, actinolite, tourmaline and hornblende. The group was so named by Haüy in allusion to the variety, in composition and appearance. This term has since applied to the whole group. Numerous sub-species and varieties are distinguished, the important of which are tabulated below in two series. The formulae of each will be seen to be built on the general double-chain silicate formula RSi4O11, four of the amphibole minerals are among the minerals commonly called asbestos. These are, anthophyllite, riebeckite, cummingtonite/grunerite series, and actinolite/tremolite series, the cummingtonite/grunerite series is often termed amosite or brown asbestos, riebeckite is known as crocidolite or blue asbestos. These are generally called amphibole asbestos, anthophyllite occurs as brownish, fibrous or lamellar masses with hornblende in mica-schist at Kongsberg in Norway and some other localities. An aluminous related species is known as gedrite and a deep green Russian variety containing little iron as kupfferite, hornblende is an important constituent of many igneous rocks. It is also an important constituent of amphibolites formed by metamorphism of basalt, actinolite is an important and common member of the monoclinic series, forming radiating groups of acicular crystals of a bright green or greyish-green color. It occurs frequently as a constituent of greenschists, the name is a translation of the old German word Strahlstein
18.
Pyroxene
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The pyroxenes are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. Pyroxenes are silicon-aluminum oxides with Ca, Na, Fe, Mg, Zn, Mn, Li substituting for Si, although aluminium substitutes extensively for silicon in silicates such as feldspars and amphiboles, the substitution occurs only to a limited extent in most pyroxenes. They share a structure consisting of single chains of silica tetrahedra. The name pyroxene is derived from the Ancient Greek words for fire, however, they are simply early-forming minerals that crystallized before the lava erupted. The upper mantle of Earth is composed mainly of olivine and pyroxene, a piece of the mantle is shown at right and is dominated by olivine, typical for common peridotite. Pyroxene and feldspar are the minerals in basalt and gabbro. Pyroxene minerals are named according to the chemical species occupying the X site, the Y site, cations in Y site are closely bound to 6 oxygens in octahedral coordination. Cations in the X site can be coordinated with 6 to 8 oxygen atoms, twenty mineral names are recognised by the International Mineralogical Associations Commission on New Minerals and Mineral Names and 105 previously used names have been discarded. A typical pyroxene has mostly silicon in the site and predominately ions with a charge of +2 in both the X and Y sites, giving the approximate formula XYT2O6. The names of the common calcium – iron – magnesium pyroxenes are defined in the pyroxene quadrilateral shown in Figure 2, the enstatite-ferrosilite series contain up to 5 mol. % calcium and exists in three polymorphs, orthorhombic orthoenstatite and protoenstatite and monoclinic clinoenstatite. Increasing the calcium content prevents the formation of the orthorhombic phases, there is not complete solid solution in calcium content and Mg-Fe-Ca pyroxenes with calcium contents between about 15 and 25 mol. % are not stable with respect to a pair of exolved crystals. This leads to a miscibility gap between pigeonite and augite compositions, there is an arbitrary separation between augite and the diopside-hedenbergite solid solution. The divide is taken at >45 mol. % Ca, as the calcium ion cannot occupy the Y site, pyroxenes with more than 50 mol. % calcium are not possible. A related mineral wollastonite has the formula of the hypothetical calcium end member, magnesium, calcium and iron are by no means the only cations that can occupy the X and Y sites in the pyroxene structure. A second important series of minerals are the sodium-rich pyroxenes. The inclusion of sodium, which has a charge of +1, in jadeite and aegirine this is added by the inclusion of a +3 cation on the Y site. Table 1 shows the range of other cations that can be accommodated in the pyroxene structure. For example, Na and Al give the jadeite composition, coupled substitution of a 1+ ion on the X site and a mixture of equal numbers of 2+ and 4+ ions on the Y site
19.
Biotite
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Biotite is a common phyllosilicate mineral within the mica group, with the approximate chemical formula K 3AlSi 3O102. Hausmann in 1847 in honor of the French physicist Jean-Baptiste Biot, iron, magnesium, aluminium, silicon, oxygen, and hydrogen form sheets that are weakly bound together by potassium ions. It is sometimes called iron mica because it is more iron-rich than phlogopite and it is also sometimes called black mica as opposed to white mica – both form in some rocks, and in some instances side-by-side. Like other mica minerals, biotite has a perfect basal cleavage, and consists of flexible sheets, or lamellae. It has a crystal system, with tabular to prismatic crystals with an obvious pinacoid termination. It has four faces and two pinacoid faces to form a pseudohexagonal crystal. Although not easily seen because of the cleavage and sheets, fracture is uneven and it appears greenish to brown or black, and even yellow when weathered. It can be transparent to opaque, has a vitreous to pearly luster, when biotite is found in large chunks, they are called “books” because it resembles a book with pages of many sheets. The color of biotite is usually black and the mineral has a hardness of 2. 5-3 on the Mohs scale of mineral hardness, biotite dissolves in both acid and alkaline aqueous solutions, with the highest dissolution rates at low pH. However, biotite dissolution is highly anisotropic with crystal edge surfaces reacting 45 to 132 times faster than basal surfaces, under cross-polarized light biotite can generally be identified by the gnarled birds eye extinction. Biotite is found in a variety of igneous and metamorphic rocks. For instance, biotite occurs in the lava of Mount Vesuvius, biotite in granite tends to be poorer in magnesium than the biotite found in its volcanic equivalent, rhyolite. Biotite is an essential phenocryst in some varieties of lamprophyre, biotite is occasionally found in large cleavable crystals, especially in pegmatite veins, as in New England, Virginia and North Carolina. Other notable occurrences include Bancroft and Sudbury, Ontario and it is an essential constituent of many metamorphic schists, and it forms in suitable compositions over a wide range of pressure and temperature. It has been estimated that biotite comprises up to 7% of the continental crust. The largest documented single crystals of biotite were approximately 7 m2 sheets found in Iveland, biotite is used extensively to constrain ages of rocks, by either potassium-argon dating or argon-argon dating. Because argon escapes readily from the crystal structure at high temperatures. Biotite is also useful in assessing temperature histories of metamorphic rocks, because the partitioning of iron and magnesium between biotite and garnet is sensitive to temperature
20.
Alkali metal
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The alkali metals are a group in the periodic table consisting of the chemical elements lithium, sodium, potassium, rubidium, caesium, and francium. Indeed, the alkali metals provide the best example of trends in properties in the periodic table. The alkali metals are all shiny, soft, highly reactive metals at standard temperature and pressure and they can all be cut easily with a knife due to their softness, exposing a shiny surface that tarnishes rapidly in air due to oxidation by atmospheric moisture and oxygen. Because of their reactivity, they must be stored under oil to prevent reaction with air. Caesium, the alkali metal, is the most reactive of all the metals. All the alkali metals react with water, with the alkali metals reacting more vigorously than the lighter ones. Experiments have been conducted to attempt the synthesis of ununennium, which is likely to be the member of the group. Most alkali metals have different applications. One of the applications of the pure elements is the use of rubidium and caesium in atomic clocks, of which caesium atomic clocks are the most accurate. A common application of the compounds of sodium is the sodium-vapour lamp, table salt, or sodium chloride, has been used since antiquity. The physical and chemical properties of the alkali metals can be explained by their having an ns1 valence electron configuration. Hence, all the metals are soft and have low densities, melting and boiling points, as well as heats of sublimation, vaporisation. They all crystallise in the cubic crystal structure, and have distinctive flame colours because their outer s electron is very easily excited. The ns1 configuration also results in the alkali metals having very large atomic and ionic radii, most of the chemistry has been observed only for the first five members of the group. The chemistry of francium is not well established due to its radioactivity, thus. What little is known about francium shows that it is close in behaviour to caesium. The physical properties of francium are even sketchier because the element has never been observed. The alkali metals are more similar to other than the elements in any other group are to each other
21.
Alkaline earth metal
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The alkaline earth metals are six chemical elements in column 2 of the Periodic table. They are beryllium, magnesium, calcium, strontium, barium, the elements have very similar properties, they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure. All the discovered alkaline earth metals occur in nature, experiments have been conducted to attempt the synthesis of element 120, the next potential member of the group, but they have all met with failure. The chemistry of radium is not well-established due to its radioactivity, thus, the alkaline earth metals are all silver-colored and soft, and have relatively low densities, melting points, and boiling points. In chemical terms, all of the alkaline metals react with the halogens to form the earth metal halides. All the alkaline earth metals except beryllium also react with water to form strongly alkaline hydroxides and, thus, the heavier alkaline earth metals react more vigorously than the lighter ones. The second ionization energy of all of the metals is also somewhat low. Beryllium is an exception, It does not react with water or steam, all compounds that include beryllium have a covalent bond. Even the compound beryllium fluoride, which is the most ionic beryllium compound, has a low melting point and a low electrical conductivity when melted. The alkaline earth metals all react with the halogens to form ionic halides, such as calcium chloride, calcium, strontium, and barium react with water to produce hydrogen gas and their respective hydroxides, and also undergo transmetalation reactions to exchange ligands. The table below is a summary of the key physical and atomic properties of the alkaline earth metals, calcium-48 is the lightest nuclide to undergo double beta decay. The natural radioisotope of calcium, calcium-48, makes up about 0. 1874% of natural calcium, barium-130 makes up approximately 0. 1062% of natural barium, and, thus, barium is weakly radioactive, as well. The alkaline earth metals are named after their oxides, the alkaline earths, whose old-fashioned names were beryllia, magnesia, lime, strontia and these oxides are basic when combined with water. Earth is an old term applied by early chemists to nonmetallic substances that are insoluble in water, the realization that these earths were not elements but compounds is attributed to the chemist Antoine Lavoisier. In his Traité Élémentaire de Chimie of 1789 he called them salt-forming earth elements, later, he suggested that the alkaline earths might be metal oxides, but admitted that this was mere conjecture. The calcium compounds calcite and lime have been known and used since prehistoric times, the same is true for the beryllium compounds beryl and emerald. The other compounds of the alkaline earth metals were discovered starting in the early 15th century, the magnesium compound magnesium sulfate was first discovered in 1618 by a farmer at Epsom in England. Strontium carbonate was discovered in minerals in the Scottish village of Strontian in 1790, the last element is the least abundant, radioactive radium, which was extracted from uraninite in 1898
22.
Continental crust
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The continental crust is the layer of igneous, sedimentary, and metamorphic rocks that forms the continents and the areas of shallow seabed close to their shores, known as continental shelves. This layer is sometimes called sial because its composition is more felsic compared to the oceanic crust. The continental crust consists of layers, with a bulk composition that is intermediate to felsic. The average density of continental crust is about 2.7 g/cm3, less dense than the material that makes up the mantle. Continental crust is less dense than oceanic crust, whose density is about 2.9 g/cm3. At 25 to 70 km, continental crust is thicker than oceanic crust. About 40% of Earths surface is occupied by continental crust. It makes up about 70% of the volume of Earths crust, because the surface of continental crust mainly lies above sea level, its existence allowed land life to evolve from marine life. There is little evidence of continental crust prior to 3.5 Ga, all continental crust ultimately derives from the fractional differentiation of oceanic crust over many eons. This process has been and continues today primarily as a result of the associated with subduction. In contrast to the persistence of continental crust, the size, shape, different tracts rift apart, collide and recoalesce as part of a grand supercontinent cycle. There are currently about 7 billion cubic kilometers of continental crust, the relative permanence of continental crust contrasts with the short life of oceanic crust. Because continental crust is less dense oceanic crust, when active margins of the two meet in subduction zones, the oceanic crust is typically subducted back into the mantle. Continental crust is rarely subducted.01 Ga, whereas the oldest oceanic crust is from the Jurassic, Continental crust and the rock layers that lie on and within it are thus the best archive of Earths history. The height of mountain ranges is usually related to the thickness of crust and this results from the isostasy associated with orogeny. The crust is thickened by the compressive forces related to subduction or continental collision, the buoyancy of the crust forces it upwards, the forces of the collisional stress balanced by gravity and erosion. This forms a keel or mountain root beneath the mountain range, the thinnest continental crust is found in rift zones, where the crust is thinned by detachment faulting and eventually severed, replaced by oceanic crust. The edges of continental fragments formed this way are termed passive margins, igneous rock may also be underplated to the underside of the crust, i. e. adding to the crust by forming a layer immediately beneath it
23.
Subduction
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Subduction is a geological process that takes place at convergent boundaries of tectonic plates where one plate moves under another and is forced or sinks due to gravity into the mantle. Regions where this occurs are known as subduction zones. Rates of subduction are typically in centimeters per year, with the rate of convergence being approximately two to eight centimeters per year along most plate boundaries. Plates include both oceanic crust and continental crust, stable subduction zones involve the oceanic lithosphere of one plate sliding beneath the continental or oceanic lithosphere of another plate due to the higher density of the oceanic lithosphere. That is, the lithosphere is always oceanic while the overriding lithosphere may or may not be oceanic. Subduction zones are sites that have a rate of volcanism, earthquakes. Subduction zones are sites of convective downwelling of Earths lithosphere, subduction zones exist at convergent plate boundaries where one plate of oceanic lithosphere converges with another plate. The descending slab, the plate, is over-ridden by the leading edge of the other plate. The slab sinks at an angle of approximately twenty-five to forty-five degrees to Earths surface and this sinking is driven by the temperature difference between the subducting oceanic lithosphere and the surrounding mantle asthenosphere, as the colder oceanic lithosphere is, on average, denser. At a depth of approximately 80–120 kilometers, the basalt of the oceanic crust is converted to a rock called eclogite. At that point, the density of the oceanic crust increases and provides additional negative buoyancy and it is at subduction zones that Earths lithosphere, oceanic crust, sedimentary layers and some trapped water are recycled into the deep mantle. Earth is so far the only planet where subduction is known to occur, subduction is the driving force behind plate tectonics, and without it, plate tectonics could not occur. Subduction zones dive down into the mantle beneath 55,000 kilometers of convergent plate margins, subduction zones burrow deeply but are imperfectly camouflaged, and geophysics and geochemistry can be used to study them. Not surprisingly, the shallowest portions of subduction zones are known best, subduction zones are strongly asymmetric for the first several hundred kilometers of their descent. They start to go down at oceanic trenches and their descents are marked by inclined zones of earthquakes that dip away from the trench beneath the volcanoes and extend down to the 660-kilometer discontinuity. Subduction zones are defined by the array of earthquakes known as the Wadati–Benioff zone after the two scientists who first identified this distinctive aspect. Subduction zone earthquakes occur at greater depths than elsewhere on Earth, such deep earthquakes may be driven by deep phase transformations, thermal runaway, the subducting basalt and sediment are normally rich in hydrous minerals and clays. Additionally, large quantities of water are introduced into cracks and fractures created as the slab bends downward
24.
Partial melting
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Partial melting occurs when only a portion of a solid is melted. For mixed substances, such as a rock containing several different minerals or a mineral that displays solid solution, partial melting occurs where the solidus and liquidus temperatures are different. For single minerals this can happen when they exhibit solid solution, in rocks made up of several different minerals, some will melt at lower temperatures than others. Partial melting is an important consideration in geology with respect to the differentiation of crustal rocks. Virtually all rocks on Earth derive from material from the interior of the earth that has been partially melted, the main places where partial melting occurs are subduction zones, mid-ocean ridges and hotspots. In all these places partial melting is often associated with volcanism, partial melts are thought to play an important role in enriching old parts of the continental lithosphere in incompatible elements. Partial melts produced at depth move upwards due to the compaction of the surrounding matrix
25.
Tonalite
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Tonalite is an igneous, plutonic rock, of felsic composition, with phaneritic texture. Feldspar is present as plagioclase with 10% or less alkali feldspar, quartz is present as more than 20% of the rock. Amphiboles and pyroxenes are common accessory minerals, in older references tonalite is sometimes used as a synonym for quartz diorite. However the current IUGS classification defines tonalite as having greater than 20% quartz, the name is derived from the type locality of tonalites, adjacent to the Tonale Line, a major structural lineament and mountain pass, Tonale Pass, in the Italian and Austrian Alps. Trondhjemite is an orthoclase-deficient variety of tonalite with minor biotite as the only mafic mineral, named after Norways third largest city, media related to Tonalite at Wikimedia Commons
26.
Nepheline syenite
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Nepheline syenite is a holocrystalline plutonic rock that consists largely of nepheline and alkali feldspar. The rocks are mostly pale colored, grey or pink, and in appearance they are not unlike granites. Phonolite is the extrusive equivalent. Nepheline syenites are silica-undersaturated and some are peralkaline, Nepheline is a feldspathoid, a solid-solution mineral, that does not coexist with quartz, rather, nepheline would react with quartz to produce alkali feldspar. Alkali feldspar dominates, commonly represented by orthoclase and the exsolved lamellar albite, in some rocks the potash feldspar, in others the soda feldspar predominates. Fresh clear microcline is very characteristic of some types of nepheline syenite, sodalite, colorless and transparent in thin section, but frequently pale blue in the hand specimens, is the principal feldspathoid mineral in addition to nepheline. Reddish-brown to black triclinic aenigmatite occurs also in these rocks, extremely iron-rich olivine is rare, but is present in some nepheline syenite. Other minerals common in minor amounts include sodium-rich pyroxene, biotite, titanite, iron oxides, apatite, fluorite, melanite garnet, a great number of interesting and rare minerals have been recorded from nepheline syenites and the pegmatite veins which intersect them. Macroscopic aspects of nepheline syenite are similar to those of granite, the presence of nepheline and absence of quartz are the fundamental difference. Biotite is generally of low content and the mafic minerals are clinopyroxene. The macroscopic colour is grey, being darker than granite. There is high-grade metamorphic rock originated from nepheline syenite that is characterized by gneiss texture of very rare occurrence and it is called nepheline syenite gneiss or litchfieldite. An example is found at Canaã village, State of Rio de Janeiro, the rock is holocrystalline, generally equigranular, equidirectional, and gross with grain size of 2 mm to 5 mm. In certain rare cases, the rock contains alkaline feldspar phenocrysts of 2 cm to 5 cm in length and 5 mm to 2 cm in thickness, the phenocrysts demonstrate orientation and eventually show cumulative texture. The main minerals are feldspar, nepheline, clinopyroxene, amphibole. According to the IUGS classification nomenclature, nepheline syenite has 10%<F/<60% and P/<10%, in case nepheline is less than 10%, the rock is called alkaline syenite with nepheline or pulaskite. The similar rock without quartz and nepheline is denominated alkaline syenite or syenite, because of the presence of feldspathoids, nepheline syenite is classified to be a typical alkaline rock. The alkaline feldspar is not potassic, but generally sodic-potassic, which is characterized by interlocking anorthoclase, in the alkali feldspar almost pure albite domains are observed
27.
Leucite
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Goniometric measurements made by Gerhard vom Rath in 1873 led him to refer the crystals to the tetragonal system. This pseudo-cubic character of leucite is very similar to that of the mineral boracite, the crystals are white or ash-grey in colour, hence the name suggested by A. G. Werner in 1701, from λευκος, white. The Mohs hardness is 5.5, and the specific gravity 2.47, inclusions of other minerals, arranged in concentric zones, are frequently present in the crystals. On account of the color and form of the crystals the mineral was known as white garnet. This article incorporates text from a now in the public domain, Chisholm, Hugh
28.
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
29.
Anorthite
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Anorthite is the calcium endmember of plagioclase feldspar. Plagioclase is an abundant mineral in the Earths crust, the formula of pure anorthite is CaAl2Si2O8. Anorthite is the calcium-rich endmember of the solid solution series. Anorthite also refers to plagioclase compositions with more than 90 molecular percent of the anorthite endmember, anorthite is a rare compositional variety of plagioclase. It occurs in igneous rock. It also occurs in rocks of granulite facies, in metamorphosed carbonate rocks. Its type localities are Monte Somma and Valle di Fassa, Italy and it was first described in 1823. It is more rare in surficial rocks than it normally would be due to its high weathering potential in the Goldich dissolution series and it also makes up much of the lunar highlands, the Genesis Rock is made of anorthosite, which is composed largely of anorthite. Anorthite was discovered in samples from comet Wild 2, and the mineral is an important constituent of Ca-Al-rich inclusions in rare varieties of chondritic meteorites
30.
Cumulate rock
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Cumulate rocks are igneous rocks formed by the accumulation of crystals from a magma either by settling or floating. Cumulate rocks are named according to their texture, cumulate texture is diagnostic of the conditions of formation of group of igneous rocks. Cumulate rocks are the product of precipitation of solid crystals from a fractionating magma chamber. These accumulations typically occur on the floor of the magma chamber, cumulates are typically found in ultramafic intrusions, in the base of large ultramafic lava tubes in komatiite and magnesium rich basalt flows and also in some granitic intrusions. Cumulates are named according to their dominant mineralogy and the percentage of crystals to their groundmass, adcumulates are rocks containing ~100–93% accumulated magmatic crystals in a fine-grained groundmass. Mesocumulates are rocks with between 93 and 85% accumulated minerals in a groundmass, orthocumulates are rocks containing between 85 and 75% accumulated minerals in groundmass. Cumulate rocks are named according to the cumulate minerals in order of abundance, and then cumulate type. For example, a layer with 50% plagioclase, 40% pyroxene, 5% olivine, a rock consisting of 80% olivine, 5% magnetite and 15% groundmass is an olivine mesocumulate. Cumulate terminology is appropriate for use when describing cumulate rocks, in intrusions which have a uniform composition and minimal textural and mineralogical layering or visible crystal accumulations it is inappropriate to describe them according to this convention. Cumulate rocks, because they are fractionates of a parental magma, the chemistry of the cumulate itself can inform on the residual melt composition, but several factors need to be considered. In this example, the precipitation of anorthite removes calcium from the melt, enstatite being precipitated from the melt will remove magnesium, so the melt becomes depleted in these elements. This tends to enrich the concentration of other elements - typically sodium, potassium, titanium, the rock that is made of the accumulated minerals will not have the same composition as the magma. In the above example, the cumulate of anorthite + enstatite is rich in calcium and magnesium, the cumulate rock is a plagioclase-pyroxene cumulate and the melt is now more felsic and aluminous in composition. In the above example, the plagioclase and pyroxene need not be pure end-member compositions, the minerals can be precipitated in any ratio within the cumulate, such cumulates can be 90% plagioclase, 10% enstatite, through to 10% plagiclase, 90% enstatite and remain a gabbro. This also alters the chemistry of the cumulate, and the depletions of the residual melt, in nature, cumulates usually form from 2 mineral species, although ranges from 1 to 4 mineral species are known. Cumulate rocks which are formed from one mineral alone are often named after the mineral, a specific example is the Skaergaard intrusion in Greenland. One way to infer the composition of the magma that created the cumulate rocks is to measure groundmass chemistry, otherwise, complex calculations of averaging cumulate layers must be utilised, which is a complex process. Alternatively, the composition can be estimated by assuming certain conditions of magma chemistry
31.
Concord, North Carolina
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Concord city in Cabarrus county, in the U. S. state of North Carolina. As of the 2010 census, the city had a population of 79,066 and it is the county seat and the largest city in Cabarrus County. In terms of population, the city of Concord is the second-largest city in the Charlotte Metropolitan Area and is the twelfth largest city in North Carolina, in 2015, Concord was ranked as the city with the 16th fastest growing economy in the United States. The city was a winner of the All-America City Award in 2004, located near the center of Cabarrus County in the Piedmont region, it is 20 miles northeast of Charlotte center city. Concord is the home to some of North Carolinas top tourist destinations, including NASCARs Charlotte Motor Speedway, Concord, located in todays rapidly growing northeast quadrant of the Charlotte metropolitan area, was first settled about 1750 by German and Scots-Irish immigrants. The name Concord means with harmony and this name was chosen after a lengthy dispute over where the county seat should be located between the German Lutherans and Scotch-Irish Presbyterians. By United States standards, Concord is considered an old town, today, markers identifying the original town limits can be seen in the downtown area. As county seat, Concord became a center of trade and retail for the cotton-producing region, the downtown would be crowded with farmers and townfolk, in addition to lawyers and their clients. During the antebellum era, wealthy was built by planters through the cultivation of cotton as a commodity crop, located in the Piedmont, Concord became a site of industrialization with cotton mills in the late 19th century. Among the owners of the new mills in the area were men of the rising black middle-class in Wilmington, North Carolina, Dancy, and others, who organized Coleman Manufacturing Company in 1897. They built and operated what is believed to have been the first cotton mill owned by blacks in the nation and they hoped to promote economic security for people of color. But the Wilmington Insurrection of 1898, with attacks on black areas of the city, caused many deaths. In 1900, Dancy was among more than 2000 blacks who left the city permanently after the riot and he moved to Washington, DC, appointed as the federal Recorder of Deeds, and serving until 1910. The mill operated under black ownership through 1904, hitting difficult times after Coleman died, the brick mill building was later taken over by Fieldcrest Cannon. Within the North Union Historic District is Memorial Garden, located on 3 acres, the garden winds through the 200-year-old cemetery of the First Presbyterian Church. From the time of incorporation in the late 1700s through the 1970s, since then, most annexations have taken place west of the center-city area towards Charlotte. Portions of the city limit boundary adjoin the Cabarrus/Mecklenburg County line, Concord is located in western Cabarrus County at 35°24′16″N 80°36′2″W. The city is located in the Piedmont area of North Carolina, land left untended will typically return to native forest land within a few years
32.
Kola Peninsula
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The Kola Peninsula is a peninsula in the far northwest of Russia. The city of Murmansk is the most populous human settlement on the peninsula, summers are rather chilly, with the average July temperature of only 11 °C. The peninsula is covered by taiga in the south and tundra in the north, the peninsula supports a small variety of mammals, and its rivers are an important habitat for the Atlantic salmon. The Kandalaksha Nature Reserve, established to protect the population of eider, is located in the Kandalaksha Gulf. However, by the 1st millennium CE only the Sami people remained and this changed in the 12th century, when Russian Pomors discovered the peninsulas game and fish riches. Soon after, the Pomors were followed by the tribute collectors from the Novgorod Republic, no permanent settlements, however, were established by the Novgorodians until the 15th century. The Novgorod Republic lost control of the peninsula to the Grand Duchy of Moscow in 1471, several new settlements were established during the 16th century, and the Sami and Pomor people were forced into serfdom. The original administrative and economic center of the area was Kola, however, in 1916, Romanov-na-Murmane was founded and quickly became the largest city and port on the peninsula. The Soviet period saw an increase of the population, although most of it remained confined to urbanized territories along the sea coast. As a result, the ecology of the peninsula suffered major damage, including contamination by military nuclear waste. After the dissolution of the Soviet Union, the economy went into decline, between 1989 and 2002, Murmansk Oblast lost almost a quarter of its population, and almost 100,000 more between 2002 and 2010. Nevertheless, the economy rebounded somewhat in the first decade of the 2000s, the peninsula is located in the far northwest of Russia, almost completely inside the Arctic Circle and is washed by the Barents Sea in the north and the White Sea in the east and southeast. Geologically, the peninsula occupies the edge of the Baltic Shield. Under a more restrictive definition, the covers a area of about 100,000 square kilometers. The northern coast is steep and high, while the southern coast is flat, the Keyvy drainage divide lies in the central part. The mountainous reliefs of the Murman and Kandalaksha Coasts stretch from southeast to northwest, deposits of construction materials such as granite, quartzite, and limestone are also abundant. Diatomaceous earth deposits are common near lakes and are used to produce insulation, cyclones are typical during the cold seasons, while the warm seasons are characterized by anticyclones. Monsoon winds are common in most areas, with south and southwesterly winds prevailing in winter months, strong storm winds blow for 80–120 days a year
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Lovozero Massif
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The slopes are covered mainly with spruce and pine. The highest point is Mount Angvundaschorr, the area around the lake is inhabited by Saami, and many place names are of non-Russian origin. The Lovozero Massif is underlain by a complex of agpaitic to hyperagpaitic rocks containing minerals as eudialyte, loparite, natrosilite, at least 105 valid minerals have been described in the massif and 39 minerals were initially discovered there. The only other areas with similar geology and mineralogy are Khibiny Massif, Ilimaussaq in SW Greenland and Mont-Saint-Hilaire, Quebec, the area is relatively well accessible from railroads. In winter the area is accessible from Khibiny Mountains via the ice of Umbozero, in summer there are usable mountain roads and trails. P. Mineralogy of Hyperagpaitic Alkaline Rocks Clarendon Press 1995 Lovozero Tundras, In Russian Geology and minerals
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Khibiny Mountains
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The massif is of oval shape of about 1,300 km2. and occupies the central part of the peninsula at a relative elevation of 900–1000 m above the surrounding plain. The mountains are not particularly high, the two highest peaks are the Yudychvumchorr, which stands 1,201 metres, and the Chasnachorr, the average elevation is 1,116 metres. The mountains form the shape of a horseshoe topped by a high plateau, the peaks are of plateau type, with steep slopes, with glaciers, icefields and snowfields in some places. The overall terrain is alpine tundra, the second, and similar mountain range of the Kola Peninsula, the Lovozero Tundras, is located about 5 km east from the easternmost point of Khibiny. The Khibiny range is rich in minerals, mainly apatite. 477 valid minerals have been reported and 108 of those are type localities or minerals first described in the Khibiny, the range is also seismically active. Khibiny mountains are mostly uninhabited, except for one of the worlds richest mineral quarries, one of the minerals discovered there is reported to have a potential as a nuclear waste radioactivity absorbent. By the foot of the massif the cities of Apatity and Kirovsk are situated, the Khibiny Mountains lie within the Kola Peninsula, a large peninsula extending from northern Russia into the Barents and White seas. The total land area of the peninsula is approximately 100,000 square kilometres and it is rich in minerals due to the removal of a layer of soil during the last ice age. Khibiny have an Arctic-moderate climate, with a winter temperature of −5 °C. However, the temperature can drop to −30 °C during the night. The Gulf Stream, which brings water to the Kolsky Peninsula from the north, moderates the climate, making it slightly warmer than other Arctic regions. info Khibiny geology
35.
Arkansas
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Arkansas is a state located in the southeastern region of the United States. Its name is of Siouan derivation from the language of the Osage denoting their related kin, the states diverse geography ranges from the mountainous regions of the Ozark and the Ouachita Mountains, which make up the U. S. Interior Highlands, to the forested land in the south known as the Arkansas Timberlands, to the eastern lowlands along the Mississippi River. Arkansas is the 29th largest by area and the 33rd most populous of the 50 United States, the capital and most populous city is Little Rock, located in the central portion of the state, a hub for transportation, business, culture, and government. The northwestern corner of the state, such as the Fayetteville–Springdale–Rogers Metropolitan Area and Fort Smith metropolitan area, is a population, education, the largest city in the eastern part of the state is Jonesboro. The largest city in the part of the state is Pine Bluff. The Territory of Arkansas was admitted to the Union as the 25th state on June 15,1836, in 1861 Arkansas withdrew from the United States and joined the Confederate States of America during the Civil War. Upon returning to the Union in 1868, the state would continue to suffer due to its reliance on slavery. White rural interests continued to dominate the politics until the Civil Rights Movement. Arkansas began to diversify its economy following World War II and relies on its service industry, aircraft, poultry, steel, tourism, cotton, and rice. The culture of Arkansas is observable in museums, theaters, novels, television shows, restaurants, wright, and physicist William L. McMillan, who was a pioneer in superconductor research, have all lived in Arkansas. The name Arkansas derives from the root as the name for the state of Kansas. The Kansa tribe of Native Americans are closely associated with the Sioux tribes of the Great Plains, the word Arkansas itself is a French pronunciation of a Quapaw word, akakaze, meaning land of downriver people or the Sioux word akakaze meaning people of the south wind. In 2007, the legislature passed a non-binding resolution declaring the possessive form of the states name to be Arkansass which has been followed increasingly by the state government. Arkansas borders Louisiana to the south, Texas to the southwest, Oklahoma to the west, Missouri to the north, as well as Tennessee, the United States Census Bureau classifies Arkansas as a southern state, sub-categorized among the West South Central States. The state line along the Mississippi River is indeterminate along much of the border with Mississippi due to these changes. Arkansas can generally be split into two halves, the highlands in the northwest half and the lowlands of the southeastern half, the highlands are part of the Southern Interior Highlands, including The Ozarks and the Ouachita Mountains. The southern lowlands include the Gulf Coastal Plain and the Arkansas Delta and this dual split can yield to general regions named northwest, southwest, northeast, southeast, or central Arkansas
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Montana
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Montana /mɒnˈtænə/ is a state in the Western region of the United States. The states name is derived from the Spanish word montaña, Montana has several nicknames, although none official, including Big Sky Country and The Treasure State, and slogans that include Land of the Shining Mountains and more recently The Last Best Place. Montana has a 545-mile border with three Canadian provinces, British Columbia, Alberta, and Saskatchewan, the state to do so. It also borders North Dakota and South Dakota to the east, Wyoming to the south, Montana is ranked 4th in size, but 44th in population and 48th in population density of the 50 United States. The western third of Montana contains numerous mountain ranges, smaller island ranges are found throughout the state. In total,77 named ranges are part of the Rocky Mountains, the eastern half of Montana is characterized by western prairie terrain and badlands. The economy is based on agriculture, including ranching and cereal grain farming. Other significant economic activities include oil, gas, coal and hard rock mining, lumber, the health care, service, and government sectors also are significant to the states economy. Millions of tourists annually visit Glacier National Park, the Little Bighorn Battlefield National Monument, the name Montana comes from the Spanish word Montaña and the Latin word Montana, meaning mountain, or more broadly, mountainous country. Montaña del Norte was the name given by early Spanish explorers to the mountainous region of the west. The name was changed by Representatives Henry Wilson and Benjamin F. Harding, when Ashley presented a bill to establish a temporary government in 1864 for a new territory to be carved out of Idaho, he again chose Montana Territory. This time Rep. Samuel Cox, also of Ohio, objected to the name, Cox complained that the name was a misnomer given most of the territory was not mountainous and that a Native American name would be more appropriate than a Spanish one. Other names such as Shoshone were suggested, but it was decided that the Committee on Territories could name it whatever they wanted, with an area of 147,040 square miles, Montana is slightly larger than Japan. It is the fourth largest state in the United States after Alaska, Texas, and California, the largest landlocked U. S. state, and the worlds 56th largest national state/province subdivision. To the north, Montana shares a 545-mile border with three Canadian provinces, British Columbia, Alberta, and Saskatchewan, the state to do so. It borders North Dakota and South Dakota to the east, Wyoming to the south, the states topography is roughly defined by the Continental Divide, which splits much of the state into distinct eastern and western regions. Most of Montanas 100 or more named mountain ranges are in the western half. The Absaroka and Beartooth ranges in the states south-central part are part of the Central Rocky Mountains
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New England
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New England is a geographical region comprising six states of the northeast United States, Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York to the west and south, the Atlantic Ocean is to the east and southeast, and Long Island Sound is to the south. Its largest metropolitan area is Greater Boston, which also includes Worcester, Manchester, ten years later, more Puritans settled north of Plymouth Colony in Boston, thus forming Massachusetts Bay Colony. Over the next 126 years, people in the region fought in four French and Indian Wars, until the British and their Iroquois allies defeated the French and their Algonquin allies in North America. In 1692, the town of Salem, Massachusetts and surrounding areas experienced one of the most infamous cases of hysteria in the history of the Western Hemisphere. The Boston Tea Party was a protest to which Britain responded with a series of punitive laws stripping Massachusetts of self-government, the confrontation led to the first battles of the American Revolutionary War in 1775, and the expulsion of the British authorities from the region in spring 1776. Each state is subdivided into small incorporated municipalities known as towns. The only unincorporated areas in the region exist in the populated northern regions of Vermont, New Hampshire. The region is one of the U. S. Census Bureaus nine regional divisions, the earliest known inhabitants of New England were American Indians who spoke a variety of the Eastern Algonquian languages. Prominent tribes included the Abenaki, Mikmaq, Penobscot, Pequot, Mohegans, Narragansett Indians, Pocumtuck, prior to the arrival of Europeans, the Western Abenakis inhabited New Hampshire, New York, and Vermont, as well as parts of Quebec and western Maine. Their principal town was Norridgewock in present-day Maine, the Penobscot lived along the Penobscot River in Maine. The Narragansett and smaller tribes under Narragansett sovereignty lived in most of modern-day Rhode Island, west of Narragansett Bay, the Wampanoag occupied southeastern Massachusetts, Rhode Island, and the islands of Marthas Vineyard and Nantucket. The Pocumtucks lived in Western Massachusetts, and the Mohegan and Pequot tribes in the Connecticut region, the Connecticut River Valley includes parts of Vermont, New Hampshire, Massachusetts, and Connecticut, and linked different indigenous communities culturally, linguistically, and politically. As early as 1600, French, Dutch, and English traders began exploring the New World, trading metal, glass, on April 10,1606, King James I of England issued a charter for each of the Virginia Companies, London and Plymouth. These were privately funded ventures, intended to land for England, conduct trade. In 1620, Plymouth in present-day Massachusetts was settled by Pilgrims from the Mayflower, in 1616, English explorer John Smith named the region New England. As the first colonists arrived in Plymouth, they wrote and signed the Mayflower Compact, the Massachusetts Bay Colony came to dominate the area and was established by royal charter in 1629 with its major town and port of Boston established in 1630. Massachusetts Puritans began to settle in Connecticut as early as 1633, roger Williams was banished from Massachusetts for heresy, led a group south, and founded Providence Plantation in the area that became the Colony of Rhode Island and Providence Plantations in 1636
38.
New York (state)
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New York is a state in the northeastern United States, and is the 27th-most extensive, fourth-most populous, and seventh-most densely populated U. S. state. New York is bordered by New Jersey and Pennsylvania to the south and Connecticut, Massachusetts, and Vermont to the east. With an estimated population of 8.55 million in 2015, New York City is the most populous city in the United States, the New York Metropolitan Area is one of the most populous urban agglomerations in the world. New York City makes up over 40% of the population of New York State, two-thirds of the states population lives in the New York City Metropolitan Area, and nearly 40% lives on Long Island. Both the state and New York City were named for the 17th-century Duke of York, the next four most populous cities in the state are Buffalo, Rochester, Yonkers, and Syracuse, while the state capital is Albany. New York has a diverse geography and these more mountainous regions are bisected by two major river valleys—the north-south Hudson River Valley and the east-west Mohawk River Valley, which forms the core of the Erie Canal. Western New York is considered part of the Great Lakes Region and straddles Lake Ontario, between the two lakes lies Niagara Falls. The central part of the state is dominated by the Finger Lakes, New York had been inhabited by tribes of Algonquian and Iroquoian-speaking Native Americans for several hundred years by the time the earliest Europeans came to New York. The first Europeans to arrive were French colonists and Jesuit missionaries who arrived southward from settlements at Montreal for trade, the British annexed the colony from the Dutch in 1664. The borders of the British colony, the Province of New York, were similar to those of the present-day state, New York is home to the Statue of Liberty, a symbol of the United States and its ideals of freedom, democracy, and opportunity. In the 21st century, New York has emerged as a node of creativity and entrepreneurship, social tolerance. On April 17,1524 Verrazanno entered New York Bay, by way of the now called the Narrows into the northern bay which he named Santa Margherita. Verrazzano described it as a vast coastline with a delta in which every kind of ship could pass and he adds. This vast sheet of water swarmed with native boats and he landed on the tip of Manhattan and possibly on the furthest point of Long Island. Verrazannos stay was interrupted by a storm which pushed him north towards Marthas Vineyard, in 1540 French traders from New France built a chateau on Castle Island, within present-day Albany, due to flooding, it was abandoned the next year. In 1614, the Dutch under the command of Hendrick Corstiaensen, rebuilt the French chateau, Fort Nassau was the first Dutch settlement in North America, and was located along the Hudson River, also within present-day Albany. The small fort served as a trading post and warehouse, located on the Hudson River flood plain, the rudimentary fort was washed away by flooding in 1617, and abandoned for good after Fort Orange was built nearby in 1623. Henry Hudsons 1609 voyage marked the beginning of European involvement with the area, sailing for the Dutch East India Company and looking for a passage to Asia, he entered the Upper New York Bay on September 11 of that year
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Gneiss
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Gneiss is a common distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks. The foliations are characterized by alternating darker and lighter colored bands, the word gneiss comes from the Middle High German verb gneist. It has occurred in English since at least 1757, gneissic rocks are usually medium- to coarse-foliated, they are largely recrystallized but do not carry large quantities of micas, chlorite or other platy minerals. Gneisses that are metamorphosed igneous rocks or their equivalent are termed granite gneisses, diorite gneisses, gneiss rocks may also be named after a characteristic component such as garnet gneiss, biotite gneiss, albite gneiss, etc. Orthogneiss designates a gneiss derived from a rock, and paragneiss is one from a sedimentary rock. Gneissose rocks have properties similar to gneiss, gneiss appears to be striped in bands, called gneissic banding. The banding is developed under high temperature and pressure conditions, the minerals are arranged into layers that appear as bands in cross section. The appearance of layers, called compositional banding, occurs because the layers, the darker bands have relatively more mafic minerals. The lighter bands contain relatively more felsic and these forces stretch out the rock like a plastic, and the original material is spread out into sheets. Another cause of banding is metamorphic differentiation, which separates different materials into different layers through chemical reactions, not all gneiss rocks have detectable banding. In kyanite gneiss, crystals of kyanite appear as random clumps in what is mainly a plagioclase matrix, henderson gneiss is found in North Carolina and South Carolina, US, east of the Brevard Shear Zone. It has deformed into two sequential forms, the second, more warped, form is associated with the Brevard Fault, and the first deformation results from displacement to the southwest. Most of the Outer Hebrides of Scotland have a formed from Lewisian gneiss. In addition to the Outer Hebrides, they form basement deposits on the Scottish mainland west of the Moine Thrust and on the islands of Coll and Tiree. These rocks are igneous in origin, mixed with metamorphosed marble, quartzite and mica schist with later intrusions of basaltic dikes. Gneisses of Archean and Proterozoic age occur in the Baltic Shield, in antiquity, gneisses were also utilized in architectural construction. They were used to erect the Sphinx of Taharqo in the Nile Valley, list of rock types Blatt, Harvey and Robert J. Tracy. Petrology, Igneous, Sedimentary and Metamorphic, 2nd ed. Freeman, mcKirdy, Alan, Roger Crofts and John Gordon
40.
Chesterfield, South Carolina
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Chesterfield is a town in Chesterfield County, South Carolina, United States. The population was 1,472 at the 2010 census and it is the county seat of Chesterfield County. At the time of the 2010 census, Chesterfield was the least populous of all of South Carolinas county seats, the East Main Street Historic District, Dr. Thomas E. Lucas House, and West Main Street Historic District are listed on the National Register of Historic Places. Chesterfield is located in northeastern Chesterfield County at 34°44′1″N 80°5′20″W, according to the United States Census Bureau, the town has a total area of 4.1 square miles, all of it land. South Carolina Highway 9 passes through the town, leading east 12 miles to Cheraw, South Carolina Highway 145 crosses SC9 near the center of town, leading southwest 21 miles to McBee and northeast 10 miles to Morven, North Carolina. South Carolina Highway 102 leads south from Chesterfield 12 miles to Patrick, as of the census of 2000, there were 1472 people,597 households, and 358 families residing in the town. The population density was 383.2 people per square mile, there were 683 housing units at an average density of 198.6 per square mile. The racial makeup of the town was 64. 64% White,34. 67% African American,0. 15% Native American,0. 09% Asian,0. 29% from other races, hispanic or Latino of any race were 0. 83% of the population. 37. 2% of all households were made up of individuals and 17. 8% had someone living alone who was 65 years of age or older, the average household size was 2.19 and the average family size was 2.86. In the town, the population was out with 23. 2% under the age of 18,7. 7% from 18 to 24,25. 7% from 25 to 44,24. 9% from 45 to 64. The median age was 41 years, for every 100 females there were 81.5 males. For every 100 females age 18 and over, there were 73.0 males, the median income for a household in the town was $25,833, and the median income for a family was $36,806. Males had an income of $31,488 versus $20,625 for females. The per capita income for the town was $16,481, about 19. 7% of families and 23. 7% of the population were below the poverty line, including 39. 0% of those under age 18 and 22. 2% of those age 65 or over. The great syenite dyke extends from Hanging Rock through Taxahaw to the Brewer, National Register of Historic Places listings in Chesterfield County, South Carolina Town of Chesterfield official website
41.
Switzerland
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Switzerland, officially the Swiss Confederation, is a federal republic in Europe. It consists of 26 cantons, and the city of Bern is the seat of the federal authorities. The country is situated in western-Central Europe, and is bordered by Italy to the south, France to the west, Germany to the north, and Austria and Liechtenstein to the east. Switzerland is a country geographically divided between the Alps, the Swiss Plateau and the Jura, spanning an area of 41,285 km2. The establishment of the Old Swiss Confederacy dates to the medieval period, resulting from a series of military successes against Austria. Swiss independence from the Holy Roman Empire was formally recognized in the Peace of Westphalia in 1648. The country has a history of armed neutrality going back to the Reformation, it has not been in a state of war internationally since 1815, nevertheless, it pursues an active foreign policy and is frequently involved in peace-building processes around the world. In addition to being the birthplace of the Red Cross, Switzerland is home to international organisations. On the European level, it is a member of the European Free Trade Association. However, it participates in the Schengen Area and the European Single Market through bilateral treaties, spanning the intersection of Germanic and Romance Europe, Switzerland comprises four main linguistic and cultural regions, German, French, Italian and Romansh. Due to its diversity, Switzerland is known by a variety of native names, Schweiz, Suisse, Svizzera. On coins and stamps, Latin is used instead of the four living languages, Switzerland is one of the most developed countries in the world, with the highest nominal wealth per adult and the eighth-highest per capita gross domestic product according to the IMF. Zürich and Geneva have each been ranked among the top cities in the world in terms of quality of life, with the former ranked second globally, according to Mercer. The English name Switzerland is a compound containing Switzer, a term for the Swiss. The English adjective Swiss is a loan from French Suisse, also in use since the 16th century. The name Switzer is from the Alemannic Schwiizer, in origin an inhabitant of Schwyz and its associated territory, the Swiss began to adopt the name for themselves after the Swabian War of 1499, used alongside the term for Confederates, Eidgenossen, used since the 14th century. The data code for Switzerland, CH, is derived from Latin Confoederatio Helvetica. The toponym Schwyz itself was first attested in 972, as Old High German Suittes, ultimately related to swedan ‘to burn’
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Germany
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Germany, officially the Federal Republic of Germany, is a federal parliamentary republic in central-western Europe. It includes 16 constituent states, covers an area of 357,021 square kilometres, with about 82 million inhabitants, Germany is the most populous member state of the European Union. After the United States, it is the second most popular destination in the world. Germanys capital and largest metropolis is Berlin, while its largest conurbation is the Ruhr, other major cities include Hamburg, Munich, Cologne, Frankfurt, Stuttgart, Düsseldorf and Leipzig. Various Germanic tribes have inhabited the northern parts of modern Germany since classical antiquity, a region named Germania was documented before 100 AD. During the Migration Period the Germanic tribes expanded southward, beginning in the 10th century, German territories formed a central part of the Holy Roman Empire. During the 16th century, northern German regions became the centre of the Protestant Reformation, in 1871, Germany became a nation state when most of the German states unified into the Prussian-dominated German Empire. After World War I and the German Revolution of 1918–1919, the Empire was replaced by the parliamentary Weimar Republic, the establishment of the national socialist dictatorship in 1933 led to World War II and the Holocaust. After a period of Allied occupation, two German states were founded, the Federal Republic of Germany and the German Democratic Republic, in 1990, the country was reunified. In the 21st century, Germany is a power and has the worlds fourth-largest economy by nominal GDP. As a global leader in industrial and technological sectors, it is both the worlds third-largest exporter and importer of goods. Germany is a country with a very high standard of living sustained by a skilled. It upholds a social security and universal health system, environmental protection. Germany was a member of the European Economic Community in 1957. It is part of the Schengen Area, and became a co-founder of the Eurozone in 1999, Germany is a member of the United Nations, NATO, the G8, the G20, and the OECD. The national military expenditure is the 9th highest in the world, the English word Germany derives from the Latin Germania, which came into use after Julius Caesar adopted it for the peoples east of the Rhine. This in turn descends from Proto-Germanic *þiudiskaz popular, derived from *þeudō, descended from Proto-Indo-European *tewtéh₂- people, the discovery of the Mauer 1 mandible shows that ancient humans were present in Germany at least 600,000 years ago. The oldest complete hunting weapons found anywhere in the world were discovered in a mine in Schöningen where three 380, 000-year-old wooden javelins were unearthed
