1.
Tombstone Courthouse State Historic Park
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Tombstone Courthouse State Historic Park is a state park of Arizona in the United States. Located in Tombstone, the park preserves the original Cochise County courthouse, the park was one of the first to be designated as a state park and in 1959 was the first to open following the 1957 establishment of the Arizona State Parks Board. The town of Tombstone was incorporated in 1879, by 1881 the town had grown to more than 7,000 population, stage robberies were no longer novel events. But more important than the lawlessness, Tombstone miners and merchants had to travel 150 dusty roundtrip miles to Tucson to record mining claims, deeds, contracts, etc. at the Pima County Courthouse. At the time, the area was part of Pima County with the county seat Tucson being a rugged two-day, Cochise county was formed in 1881 from the eastern part of Pima County, and Tombstone became its seat. A new courthouse was built the year and housed all of the county’s offices. The Sheriff of Cochise County had his office on the floor, first door to the right. Sheriff John Behan and his successors gradually instilled the idea that the arena for conflict was the courtroom upstairs rather than the street. Except for the Earp - Clanton feud, which gave Tombstone an extremely bad press from which it has no interest in recovering, the Tombstone courthouse represents a practical solution to the problem of securing lives and property in unorganized or poorly governed territory. It was put into effect quickly, without fumbling by men practiced in the process through their experience in Colorado, Utah, Nevada, Tombstone remained the county seat until 1929, when outvoted by a growing Bisbee, and the county seat was moved there. The last county office left the courthouse in 1931, except for an ill-fated attempt to convert the courthouse into a hotel during the 1940s, the building stood vacant until 1955. When the Tombstone Restoration Commission acquired it, they began the courthouse rehabilitation and it features exhibits and thousands of artifacts which tell of Tombstones colorful past. The courthouse in Tombstone is an elegant example of Territorial Victorian, the Tombstone courthouse is the oldest courthouse still standing in Arizona, At the time it was built it was one of the largest buildings in Arizona Territory. The building measures 76 feet in width, the shaft of the cruciform structure measures 40 feet wide. The first segment to be built is 88 feet long overall, the addition to the jail and courtroom brought the total to 116 feet in length. The building is a red brick structure built with five courses of runners. Exterior angles are quoined with white stone and/white stone dripstone course separates the lower and upper half of the building, a one story cupola or observation tower with a mansard roof wears a lacy gingerbread cresting that creates a kind of widows walk atop all. The double-hung eight-pane windows, are set in heavy frames topped by a bracketed, the eave-line is deeply recessed and strongly accented with simple dentils as are the pediments of the gable ends
2.
Arizona
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Arizona is a state in the southwestern region of the United States. It is also part of the Western United States and the Mountain West states and it is the sixth largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix, Arizona is one of the Four Corners states. It has borders with New Mexico, Utah, Nevada, California, and Mexico, Arizonas border with Mexico is 389 miles long, on the northern border of the Mexican states of Sonora and Baja California. Arizona is the 48th state and last of the states to be admitted to the Union. Historically part of the territory of Alta California in New Spain, after being defeated in the Mexican–American War, Mexico ceded much of this territory to the United States in 1848. The southernmost portion of the state was acquired in 1853 through the Gadsden Purchase, Southern Arizona is known for its desert climate, with very hot summers and mild winters. There are ski resorts in the areas of Flagstaff, Alpine, in addition to the Grand Canyon National Park, there are several national forests, national parks, and national monuments. To the European settlers, their pronunciation sounded like Arissona, the area is still known as alĭ ṣonak in the Oodham language. Another possible origin is the Basque phrase haritz ona, as there were numerous Basque sheepherders in the area, There is a misconception that the states name originated from the Spanish term Árida Zona. See also lists of counties, islands, rivers, lakes, state parks, national parks, Arizona is in the Southwestern United States as one of the Four Corners states. Arizona is the sixth largest state by area, ranked after New Mexico, of the states 113,998 square miles, approximately 15% is privately owned. The remaining area is public forest and park land, state trust land, Arizona is well known for its desert Basin and Range region in the states southern portions, which is rich in a landscape of xerophyte plants such as the cactus. This regions topography was shaped by volcanism, followed by the cooling-off. Its climate has hot summers and mild winters. The state is well known for its pine-covered north-central portion of the high country of the Colorado Plateau. Like other states of the Southwest United States, Arizona has an abundance of mountains, despite the states aridity, 27% of Arizona is forest, a percentage comparable to modern-day France or Germany. The worlds largest stand of pine trees is in Arizona
3.
Gold
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Gold is a chemical element with symbol Au and atomic number 79. In its purest form, it is a bright, slightly yellow, dense, soft, malleable. Chemically, gold is a metal and a group 11 element. It is one of the least reactive chemical elements and is solid under standard conditions, Gold often occurs in free elemental form, as nuggets or grains, in rocks, in veins, and in alluvial deposits. It occurs in a solid solution series with the element silver and also naturally alloyed with copper. Less commonly, it occurs in minerals as gold compounds, often with tellurium, golds atomic number of 79 makes it one of the higher numbered, naturally occurring elements. It is thought to have produced in supernova nucleosynthesis, from the collision of neutron stars. Because the Earth was molten when it was formed, almost all of the present in the early Earth probably sank into the planetary core. Gold is resistant to most acids, though it does dissolve in aqua regia, a mixture of acid and hydrochloric acid. Gold also dissolves in solutions of cyanide, which are used in mining and electroplating. Gold dissolves in mercury, forming amalgam alloys, but this is not a chemical reaction, as a precious metal, gold has been used for coinage, jewelry, and other arts throughout recorded history. A total of 186,700 tonnes of gold is in existence above ground, the world consumption of new gold produced is about 50% in jewelry, 40% in investments, and 10% in industry. Gold is also used in infrared shielding, colored-glass production, gold leafing, certain gold salts are still used as anti-inflammatories in medicine. As of 2014, the worlds largest gold producer by far was China with 450 tonnes, Gold is cognate with similar words in many Germanic languages, deriving via Proto-Germanic *gulþą from Proto-Indo-European *ǵʰelh₃-. The symbol Au is from the Latin, aurum, the Latin word for gold, the Proto-Indo-European ancestor of aurum was *h₂é-h₂us-o-, meaning glow. This word is derived from the root as *h₂éu̯sōs, the ancestor of the Latin word Aurora. This etymological relationship is presumably behind the frequent claim in scientific publications that aurum meant shining dawn, Gold is the most malleable of all metals, a single gram can be beaten into a sheet of 1 square meter, and an avoirdupois ounce into 300 square feet. Gold leaf can be thin enough to become semi-transparent
4.
Ore
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An ore is a type of rock that contains sufficient minerals with important elements including metals that can be economically extracted from the rock. The ores are extracted from the earth through mining, they are refined to extract the valuable element. The grade or concentration of an ore mineral, or metal, as well as its form of occurrence, will directly affect the costs associated with mining the ore. The cost of extraction must thus be weighed against the value contained in the rock to determine what ore can be processed. Metal ores are generally oxides, sulfides, silicates, or native metals that are not commonly concentrated in the Earths crust, the ores must be processed to extract the metals of interest from the waste rock and from the ore minerals. Ore bodies are formed by a variety of geological processes, the process of ore formation is called ore genesis. An ore deposit is an accumulation of ore and this is distinct from a mineral resource as defined by the mineral resource classification criteria. An ore deposit is one occurrence of a particular ore type, Ore deposits are classified according to various criteria developed via the study of economic geology, or ore genesis. Stratiform arkose-hosted and shale-hosted copper, typified by the Zambian copperbelt and this identifies, early on, whether further investment in estimation and engineering studies is warranted and identifies key risks and areas for further work. This is because the distribution of ores is unequal and dislocated from locations of peak demand. Other, lesser, commodities do not have international clearing houses and benchmark prices and this generally makes determining the price of ores of this nature opaque and difficult. Such metals include lithium, niobium-tantalum, bismuth, antimony and rare earths, most of these commodities are also dominated by one or two major suppliers with >60% of the worlds reserves. The London Metal Exchange aims to add uranium to its list of metals on warrant, the World Bank reports that China was the top importer of ores and metals in 2005 followed by the USA and Japan. Economic geology Mineral resource classification Ore genesis Petrology Froth Flotation Extractive metallurgy DILL, the “chessboard” classification scheme of mineral deposits, Mineralogy and geology from aluminum to zirconium, Earth-Science Reviews, Volume 100, Issue 1-4, June 2010, Pages 1-420
5.
Metal
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A metal is a material that is typically hard, opaque, shiny, and has good electrical and thermal conductivity. Metals are generally malleable—that is, they can be hammered or pressed permanently out of shape without breaking or cracking—as well as fusible and ductile, about 91 of the 118 elements in the periodic table are metals, the others are nonmetals or metalloids. Some elements appear in both metallic and non-metallic forms, astrophysicists use the term metal to collectively describe all elements other than hydrogen and helium, the simplest two, in a star. The star fuses smaller atoms, mostly hydrogen and helium, to larger ones over its lifetime. In that sense, the metallicity of an object is the proportion of its matter made up of all chemical elements. Many elements and compounds that are not normally classified as metals become metallic under high pressures, the atoms of metallic substances are typically arranged in one of three common crystal structures, namely body-centered cubic, face-centered cubic, and hexagonal close-packed. In bcc, each atom is positioned at the center of a cube of eight others, in fcc and hcp, each atom is surrounded by twelve others, but the stacking of the layers differs. Some metals adopt different structures depending on the temperature, atoms of metals readily lose their outer shell electrons, resulting in a free flowing cloud of electrons within their otherwise solid arrangement. This provides the ability of metallic substances to easily transmit heat, while this flow of electrons occurs, the solid characteristic of the metal is produced by electrostatic interactions between each atom and the electron cloud. This type of bond is called a metallic bond, Metals are usually inclined to form cations through electron loss, reacting with oxygen in the air to form oxides over various timescales. Examples,4 Na + O2 →2 Na2O2 Ca + O2 →2 CaO4 Al +3 O2 →2 Al2O3, the transition metals are slower to oxidize because they form a passivating layer of oxide that protects the interior. Others, like palladium, platinum and gold, do not react with the atmosphere at all, some metals form a barrier layer of oxide on their surface which cannot be penetrated by further oxygen molecules and thus retain their shiny appearance and good conductivity for many decades. The oxides of metals are generally basic, as opposed to those of nonmetals, exceptions are largely oxides with very high oxidation states such as CrO3, Mn2O7, and OsO4, which have strictly acidic reactions. Painting, anodizing or plating metals are good ways to prevent their corrosion, however, a more reactive metal in the electrochemical series must be chosen for coating, especially when chipping of the coating is expected. Water and the two form an electrochemical cell, and if the coating is less reactive than the coatee. Metals in general have high conductivity, high thermal conductivity. Typically they are malleable and ductile, deforming under stress without cleaving, in terms of optical properties, metals are shiny and lustrous. Sheets of metal beyond a few micrometres in thickness appear opaque, although most metals have higher densities than most nonmetals, there is wide variation in their densities, lithium being the least dense solid element and osmium the densest
6.
Alloy
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An alloy is a mixture of metals or a mixture of a metal and another element. Alloys are defined by a metallic bonding character, an alloy may be a solid solution of metal elements or a mixture of metallic phases. Intermetallic compounds are alloys with a stoichiometry and crystal structure. Zintl phases are sometimes considered alloys depending on bond types. Alloys are used in a variety of applications. In some cases, a combination of metals may reduce the overall cost of the material while preserving important properties, in other cases, the combination of metals imparts synergistic properties to the constituent metal elements such as corrosion resistance or mechanical strength. Examples of alloys are steel, solder, brass, pewter, duralumin, bronze, the alloy constituents are usually measured by mass. Alloys are usually classified as substitutional or interstitial alloys, depending on the arrangement that forms the alloy. They can be classified as homogeneous, or heterogeneous or intermetallic. An alloy is a mixture of elements, which forms an impure substance that retains the characteristics of a metal. Alloys are made by mixing two or more elements, at least one of which is a metal and this is usually called the primary metal or the base metal, and the name of this metal may also be the name of the alloy. The other constituents may or may not be metals but, when mixed with the base, they will be soluble. The mechanical properties of alloys will often be different from those of its individual constituents. A metal that is very soft, such as aluminium, can be altered by alloying it with another soft metal. Although both metals are soft and ductile, the resulting aluminium alloy will have much greater strength. Adding a small amount of carbon to iron trades its great ductility for the greater strength of an alloy called steel. Due to its strength, but still substantial toughness, and its ability to be greatly altered by heat treatment, steel is one of the most useful. By adding chromium to steel, its resistance to corrosion can be enhanced, creating stainless steel, while adding silicon will alter its electrical characteristics, producing silicon steel
7.
Precious metal
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A precious metal is a rare, naturally occurring metallic chemical element of high economic value. Chemically, the precious metals tend to be less reactive than most elements and they are usually ductile and have a high lustre. Historically, precious metals were important as currency but are now regarded mainly as investment, Gold, silver, platinum, and palladium each have an ISO4217 currency code. The best known precious metals are the metals, gold. Although both have industrial uses, they are known for their uses in art, jewelry, fine jewelry. Other precious metals include the platinum metals, ruthenium, rhodium, palladium, osmium, iridium. The demand for metals is driven not only by their practical use but also by their role as investments. Historically, precious metals have commanded much higher prices than common industrial metals, a metal is deemed to be precious if it is rare. The discovery of new sources of ore or improvements in mining or refining processes may cause the value of a metal to diminish. The status of a metal can also be determined by high demand or market value. Precious metals in bulk form are known as bullion and are traded on commodity markets, bullion metals may be cast into ingots or minted into coins. The defining attribute of bullion is that it is valued by its mass, the level of purity varies from issue to issue. The purest mass-produced bullion coins are in the Canadian Gold Maple Leaf series, a 100% pure bullion is nearly impossible, as the percentage of impurities diminishes, it becomes progressively more difficult to purify the metal further. Historically, coins had an amount of weight of alloy. The Krugerrand is the first modern example of measuring in pure gold, other bullion coins show neither the purity nor the fine-gold weight on the coin but are recognized and consistent in their composition. Many coins historically showed a denomination in currency, although nominally issued as legal tender, these coins face value as currency is far below that of their value as bullion. For instance, Canada mints a gold coin at a face value of $50 containing one troy ounce of gold—as of May 2011. Bullion coins minting by national governments gives them some numismatic value in addition to their bullion value, one of the largest bullion coins in the world was the 10, 000-dollar Australian Gold Nugget coin minted in Australia which consists of a full kilogram of 99. 9% pure gold
8.
Titration
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Titration, also known as titrimetry, is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte. Since volume measurements play a key role in titration, it is known as volumetric analysis. A reagent, called the titrant or titrator is prepared as a standard solution, a known concentration and volume of titrant reacts with a solution of analyte or titrand to determine concentration. The volume of titrant reacted is called titration volume, the word titration comes from the Latin word titulus, meaning inscription or title. The French word titre, also from this origin, means rank, volumetric analysis originated in late 18th-century France. François-Antoine-Henri Descroizilles developed the first burette in 1791, joseph Louis Gay-Lussac developed an improved version of the burette that included a side arm, and coined the terms pipette and burette in an 1824 paper on the standardization of indigo solutions. Depending on the endpoint desired, single drops or less than a drop of the titrant can make the difference between a permanent and temporary change in the indicator. Typical titrations require titrant and analyte to be in a liquid form, though solids are usually dissolved into an aqueous solution, other solvents such as glacial acetic acid or ethanol are used for special purposes. Concentrated analytes are diluted to improve accuracy. Many non-acid-base titrations require a constant pH throughout the reaction, therefore, a buffer solution may be added to the titration chamber to maintain the pH. Some redox reactions may require heating the solution and titrating while the solution is still hot to increase the reaction rate. For instance, the oxidation of some oxalate solutions requires heating to 60 °C to maintain a rate of reaction. In an acid-base titration, the titration curve reflects the strength of the corresponding acid, for a strong acid and a strong base, the curve will be relatively smooth and very steep near the equivalence point. Because of this, a change in titrant volume near the equivalence point results in a large pH change. If one reagent is an acid or base and the other is a strong acid or base, the titration curve is irregular. For example, the curve for the titration between oxalic acid and sodium hydroxide is pictured. The equivalence point occurs between pH 8-10, indicating the solution is basic at the point and an indicator such as phenolphthalein would be appropriate. Titrations between an acid and a weak base have titration curves which are highly irregular
9.
Cupellation
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Since the Early Bronze Age, the process was used to obtain silver from smelted lead ores. By the Middle Ages and the Renaissance, cupellation was one of the most common processes for refining precious metals. By then, fire assays were used for assaying minerals, that is, testing fresh metals such as lead and recycled metals to know their purity for jewellery, cupellation is still in use today. Native silver is an element, although it exists as such. It is usually found in combined with other metals, or in minerals that contain silver compounds. So the primary production of silver requires the smelting and then cupellation of argentiferous lead ores, Lead melts at 327°C, lead oxide at 888°C and silver melts at 960°C. To separate the silver, the alloy is melted again at the temperature of 960°C to 1000°C in an oxidizing environment. The lead oxidises to lead monoxide, then known as litharge, the liquid lead oxide is removed or absorbed by capillary action into the hearth linings. The lining had to be calcareous because lead reacts with silica to form lead silicate that prevents the needed absorption of litharge. Some of the litharge evaporates, and the rest is absorbed by the porous earth lining to form litharge cakes, litharge cakes are usually circular or concavo-convex, about 15 cm in diameter. They are the most common evidence of cupellation in the Early Bronze Age. By their chemical composition, archaeologists can tell what kind of ore was treated, its components. This permits insights about production process, trade, social needs or economic situations, small scale cupellation is based on the same principle as the one done in a cupellation hearth, the main difference lies in the amount of material to be tested or obtained. The minerals have to be crushed, roasted and smelted to concentrate the metallic components in order to separate the noble metals. By the Renaissance the use of the cupellation processes was diverse, assay of ores from the mines and it was carried out in small shallow recipients known as cupels. As the main purpose of small scale cupellation was to assay and test minerals and metals, pure lead has to be added to the matter being tested to guarantee the further separation of the impurities. After the litharge has been absorbed by the cupel, buttons of silver were formed and settled in the middle of the cupel, if the alloy also contained a certain amount of gold, it settled with the silver and both had to be separated by parting. The primary tool for small scale cupellation was the cupel, cupels were manufactured in a very careful way
10.
Hallmark
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A hallmark is an official mark or series of marks struck on items made of precious metals—platinum, gold, silver and in some nations, palladium. In a more general sense, the term hallmark can also be used to refer to any distinguishing characteristic, historically, hallmarks were applied by a trusted party, the guardians of the craft or more recently by an assay office. Hallmarks are a guarantee of certain purity or fineness of the metal, Hallmarks are often confused with trademarks or makers marks. A hallmark is not the mark of a manufacturer to distinguish his products from other manufacturers products, to be a true hallmark, it must be the guarantee of an independent body or authority that the contents are as marked. Thus, a stamp of 925 by itself is not, strictly speaking, a hallmark, many nations require, as a prerequisite to official hallmarking, that the maker or sponsor itself marks upon the item a responsibility mark and a claim of fineness. Responsibility marks are required in the U. S. if metal fineness is claimed. In some nations, such as the UK, the hallmark is made up of elements, including, a mark denoting the type of metal, the maker/sponsors mark. In England, the year of marking commences on May 19, in other nations, such as Poland, the hallmark is a single mark indicating metal and fineness, augmented by a responsibility mark. These can ease import obligations among and between the signatory states, signatory countries each have a single representative hallmark which would be struck next to the Convention mark which represents the metal and fineness. The control or inspection of precious metals was an ancient concept of examination and marking, a series or system of five marks has been found on Byzantine silver dating from this period, though their interpretation is still not completely resolved. From the Late Middle Ages, hallmarking was administered by local governments through authorized assayers and these assayers examined precious metal objects, under the auspices of the state, before the object could be offered for public sale. By the age of the Craft Guilds, the authorized examiners mark was the masters mark, at one time, there was no distinction between silversmiths and goldsmiths, who were all referred to as orfèvres, the French word for goldsmith. The Master Craftsman was responsible for the quality of the work that left his atelier or workshop, hence the responsibility mark is still known today in French as le poinçon de maître literally the makers punch. Hallmarking is Europes earliest form of consumer protection, modern hallmarking in Europe appears first in France, with the Goldsmiths Statute of 1260 promulgated under Etienne Boileau, Provost of Paris, for King Louis IX. A standard for silver was thus established, in 1275, King Philip III prescribed, by royal decree, the mark for use on silver works, along with specific punches for each communitys smiths. In 1313, his successor, Philippe IV the Fair expanded the use of hallmarks to gold works, in 1327 King Edward III of England granted a charter to the Worshipful Company of Goldsmiths, marking the beginning of the Companys formal existence. This entity was headquartered in London at Goldsmiths Hall, from whence the English term hallmark is derived, although gold was certainly used for articles, the regulation was silent on standards and hallmarking for gold. In 1355, individual maker marks were introduced in France and this concept was later mirrored in England in 1363, adding accountability to the two systems
11.
X-ray fluorescence
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X-ray fluorescence is the emission of characteristic secondary X-rays from a material that has been excited by bombarding with high-energy X-rays or gamma rays. When materials are exposed to short-wavelength X-rays or to gamma rays, ionization consists of the ejection of one or more electrons from the atom, and may occur if the atom is exposed to radiation with an energy greater than its ionization energy. X-rays and gamma rays can be enough to expel tightly held electrons from the inner orbitals of the atom. The removal of an electron in this way makes the structure of the atom unstable. In falling, energy is released in the form of a photon, thus, the material emits radiation, which has energy characteristic of the atoms present. The term fluorescence is applied to phenomena in which the absorption of radiation of a specific energy results in the re-emission of radiation of a different energy, each element has electronic orbitals of characteristic energy. Following removal of an electron by an energetic photon provided by a primary radiation source. There are a number of ways in which this can happen. The main transitions are given names, an L→K transition is traditionally called Kα, an M→K transition is called Kβ, an M→L transition is called Lα, and so on. Each of these transitions yields a fluorescent photon with an energy equal to the difference in energy of the initial and final orbital. Once sorted, the intensity of each characteristic radiation is directly related to the amount of element in the material. This is the basis of a technique in analytical chemistry. Figure 2 shows the form of the sharp fluorescent spectral lines obtained in the wavelength-dispersive method. In order to excite the atoms, a source of radiation is required, conventional X-ray generators are most commonly used, because their output can readily be tuned for the application, and because higher power can be deployed relative to other techniques. However, gamma ray sources can be used without the need for a power supply. When the energy source is a synchrotron or the X-rays are focused by an optic like a polycapillary, as a result, atomic information on the sub-micrometre scale can be obtained. X-ray generators in the range 20–60 kV are used, which allow excitation of a range of atoms. The continuous spectrum consists of bremsstrahlung radiation, radiation produced when high-energy electrons passing through the tube are progressively decelerated by the material of the tube anode, a typical tube output spectrum is shown in figure 3
12.
Touchstone (assaying tool)
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A touchstone is a small tablet of dark stone such as fieldstone, slate, or lydite, used for assaying precious metal alloys. It has a finely grained surface on which soft metals leave a visible trace, the touchstone was used in ancient Greece. It was also used by the Indus Valley Civilization about 3500 BC for testing the purity of soft metals and its role in the introduction of monetary economy was explored by science historian James Burke in the second episode of his 1978 BBC television series Connections. Drawing a line with gold on a touchstone will leave a visible trace, because different alloys of gold have different colours the unknown sample can be compared to samples of known purity. This method has been used since ancient times, in modern times, additional tests can be done. The trace will react in different ways to specific concentrations of acid or aqua regia. Thus,24 carat gold is not affected but 14 carat gold will show chemical activity
13.
Radiolarite
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Radiolarite is a siliceous, comparatively hard, fine-grained, chert-like, and homogeneous sedimentary rock that is composed predominantly of the microscopic remains of radiolarians. This term is used for indurated radiolarian oozes and sometimes as a synonym of radiolarian earth. However, radiolarian earth is regarded by Earth scientists to be the unconsolidated equivalent of a radiolarite. A radiolarian chert is well-bedded, microcrystalline radiolarite that has a well-developed siliceous cement or groundmass, radiolarites are biogenic, marine, finely layered sedimentary rocks. The layers reveal an interchange of clastic mica grains, radiolarian tests, carbonates, clay minerals are usually not abundant. Radiolarites deposited in shallow depths can interleave with carbonate layers. Yet most often radiolarites are pelagic, deep water sediments, radiolarites are very brittle rocks and hard to split. They break conchoidally with sharp edges, during weathering they decompose into small, rectangular pieces. The colors range from light to dark via red, green, radiolarites are composed mainly of radiolarian tests and their fragments. The skeletal material consists of amorphous silica, radiolarians are marine, planktonic protists with an inner skeleton. Their sizes range from 0.1 to 0.5 millimeters, amongst their major orders albaillellaria, ectinaria, the spherical spumellaria and the hood-shaped nassellaria can be distinguished. According to Takahashi radiolarians stay for 2 to 6 weeks in the zone before they start sinking. Their descent through 5000 meters of water can take from two weeks to as long as 14 months. As soon as the protist dies and starts decaying silica dissolution affects the skeleton, the dissolution of silica in the oceans parallels the temperature/depth curve and is most effective in the uppermost 750 meters of the water column, farther below it rapidly diminishes. Upon reaching the interface the dissolution drastically increases again. Several centimeters below this interface the dissolution continues also within the sediment and it is in fact astonishing that any radiolarian tests survive at all. It is estimated that only as little as one percent of the skeletal material is preserved in radiolarian oozes. The organic wrappings act as a protection for the tests and spare them from dissolution, after deposition diagenetic processes start affecting the freshly laid down sediment
14.
Slate
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Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. It is the finest grained foliated metamorphic rock, foliation may not correspond to the original sedimentary layering, but instead is in planes perpendicular to the direction of metamorphic compression. The foliation in slate is called slaty cleavage and it is caused by strong compression causing fine grained clay flakes to regrow in planes perpendicular to the compression. Slate is frequently grey in color, especially when seen, en masse, Slate is not to be confused with shale, from which it may be formed, or schist. The word slate is used for certain types of object made from slate rock. It may mean a single roofing tile made of slate, or a writing slate and this was traditionally a small smooth piece of the rock, often framed in wood, used with chalk as a notepad or noticeboard, and especially for recording charges in pubs and inns. The phrases clean slate and blank slate come from this usage, before the mid-19th century, the terms slate, shale and schist were not sharply distinguished. In the context of underground mining in the United States. For example, roof slate referred to shale above a coal seam, occasionally, as in the purple slates of North Wales, ferrous reduction spheres form around iron nuclei, leaving a light green spotted texture. These spheres are sometimes deformed by a subsequent applied stress field to ovoids, Slate can be made into roofing slates, a type of roof shingle, or more specifically a type of roof tile, which are installed by a slater. Slate has two lines of breakability – cleavage and grain – which make it possible to split the stone into thin sheets, when broken, slate retains a natural appearance while remaining relatively flat and easy to stack. Slate is particularly suitable as a material as it has an extremely low water absorption index of less than 0. 4%. In fact, this natural slate, which requires only minimal processing, has the lowest embodied energy of all roofing materials, natural slate is used by building professionals as a result of its beauty and durability. Slate is incredibly durable and can last several hundred years, often little or no maintenance. Its low water makes it very resistant to frost damage and breakage due to freezing. Natural slate is also fire resistant and energy efficient, Slate roof tiles are usually fixed either with nails, or with hooks as is common with Spanish slate. In the UK, fixing is typically with double nails onto timber battens or nailed directly onto timber sarking boards, nails were traditionally of copper, although there are modern alloy and stainless steel alternatives. Both these methods, if used properly, provide a long-lasting weathertight roof with a lifespan of around 80–100 years, Slate roofs are still used today
15.
Streak (mineralogy)
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The streak of a mineral is the color of the powder produced when it is dragged across an un-weathered surface. If no streak seems to be made, the streak is said to be white or colorless. Streak is particularly important as a diagnostic for opaque and colored materials and it is less useful for silicate minerals, most of which have a white streak or are too hard to powder easily. The apparent color of a mineral can vary widely because of impurities or a disturbed macroscopic crystal structure. Small amounts of an impurity that strongly absorbs a particular wavelength can radically change the wavelengths of light that are reflected by the specimen, and thus change the apparent color. However, when the specimen is dragged to produce a streak, it is broken into randomly oriented microscopic crystals, the surface across which the mineral is dragged is called a streak plate, and is generally made of unglazed porcelain tile. In the absence of a plate, the unglazed underside of a porcelain bowl or vase or the back of a glazed tile will work. Sometimes a streak is more easily or accurately described by comparing it with the streak made by another streak plate. Because the trail left behind results from the mineral being crushed into powder, in case of harder minerals, the color of the powder can be determined by filing or crushing with a hammer a small sample, which is then usually rubbed on a streak plate. Most minerals that are harder have a white streak. Some minerals leave a similar to their natural color, such as cinnabar. Other minerals leave surprising colors, such as fluorite, which always has a streak, although it can appear in purple, blue, yellow. Hematite, which is black in appearance, leaves a red streak which accounts for its name, galena, which can be similar in appearance to hematite, is easily distinguished by its gray streak. Hamilton, W. R. Cambridge Guide to Minerals, Rocks, the Encyclopedia of Gemstones and Minerals. New York, Facts on File. p.251, physical Characteristics of Minerals, at Introduction to Mineralogy by Andrea Bangert What is Streak
16.
Colored gold
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Pure gold is slightly reddish yellow in color, but colored gold in various other colors can be produced. White gold is an alloy of gold and at least one metal, usually nickel. Like yellow gold, the purity of gold is given in karats. White golds properties vary depending on the metals and proportions used, the term white gold is used very loosely in the industry to describe karat gold alloys with a whitish hue. It is a misconception that the color of the rhodium plating. The term white covers a spectrum of colors that borders or overlaps pale yellow, tinted brown. The jewelry industry often conceals these off-white colors by rhodium plating, a common white gold formulation consists of 90 wt. % gold and 10 wt. % nickel. Copper can be added to increase malleability, the strength of gold–nickel–copper alloys is caused by formation of two phases, a gold-rich Au–Cu, and a nickel-rich Ni–Cu, and the resulting hardening of the material. The alloys used in industry are gold–palladium–silver and gold–nickel–copper–zinc. Palladium and nickel act as primary bleaching agents for gold, zinc acts as a bleaching agent to attenuate the color of copper. The nickel used in white gold alloys can cause an allergic reaction when worn over long periods. This reaction, typically a minor skin rash from nickel dermatitis, occurs in one out of eight people and because of this. Rose gold is a gold and copper alloy used for specialized jewelry. Rose gold, also known as gold and red gold, was popular in Russia at the beginning of the nineteenth century. Rose gold jewelry is becoming popular in the 21st century and is commonly used for wedding rings, bracelets. Although the names are used interchangeably, the difference between red, rose, and pink gold is the copper content, the higher the copper content. Pink gold uses the least copper, followed by rose gold, up to 15% zinc can be added to copper-rich alloys to change their color to reddish yellow or dark yellow. During ancient times, due to impurities in the smelting process and this is why many Greco-Roman texts, and even many texts from the Middle Ages, describe gold as red
17.
De re metallica
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De re metallica is a book cataloguing the state of the art of mining, refining, and smelting metals, published a year posthumously in 1556 due to a delay in preparing woodcuts for the text. The author was Georg Bauer, whose pen name was the Latinized Georgius Agricola, the book remained the authoritative text on mining for 180 years after its publication. It was also an important chemistry text for the period and is significant in the history of chemistry, mining was typically left to professionals, craftsmen and experts who were not eager to share their knowledge. Much experiential knowledge had been accumulated over the course of time and this knowledge was consecutively handed down orally within a small group of technicians and mining overseers. In the Middle Ages these people held the leading role as the master builders of the great cathedrals. It was a small, cosmopolitan elite within which existing knowledge was passed on and further developed, only a few writers from that time wrote anything about mining itself. Partly, that was because this knowledge was very difficult to access, most writers also found it simply not worth the effort to write about it. Only in the Renaissance did this begin to change. With the improved transport and the invention of the printing press knowledge spread much more easily, in 1500, the first printed book dedicated to mining engineering, called the “Nutzlich Bergbuchleyn” by Ulrich Rulein von Calw, was published. The most important works in this genre were, however, the twelve books De Re Metallica by Georgius Agricola, Agricola had spent nine years in the Bohemian town of Joachimsthal, now in the Czech Republic. After Joachimsthal, he spent the rest of his life in Chemnitz, both Joachimsthal and Chemnitz are in the Erzgebirge, or Ore Mountains. The book was influential, and for more than a century after it was published. The German mining technology it portrayed was acknowledged as the most advanced at the time, the book was reprinted in a number of Latin editions, as well as in German and Italian translations. Publication in Latin meant that it could be read by any educated European of the time, the numerous woodcuts and detailed descriptions of machinery made it a practical reference for those wishing to replicate the latest in mining technology. In 1912, the first English translation of De Re Metallica was privately published in London by subscription, the translators were Herbert Hoover, a mining engineer, and his wife, Lou Henry Hoover, a geologist and Latinist. The translation is not only for its clarity of language, but for the extensive footnotes. The most important translation—outside English—was the one published by the Deutsches Museum in Munich The book consists of a preface and twelve chapters, labelled books I to XII and it also has numerous woodcuts that provide annotated diagrams illustrating equipment and processes described in the text. Agricola addresses the book to prominent German aristocrats, the most important of whom were Maurice, Elector of Saxony and his brother Augustus and he then describes the works of ancient and contemporary writers on mining and metallurgy, the chief ancient source being Pliny the Elder
18.
Electrolysis
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In chemistry and manufacturing, electrolysis is a technique that uses a direct electric current to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially important as a stage in the separation of elements from naturally occurring sources such as using an electrolytic cell. The voltage that is needed for electrolysis to occur is called the decomposition potential, nevertheless, electrolysis, as a tool to study chemical reactions and obtain pure elements, precedes the coinage of the term and formal description by Faraday. 1785 – Martinus van Marums electrostatic generator was used to reduce tin, zinc,1800 – William Nicholson and Anthony Carlisle, decomposed water into hydrogen and oxygen. 1808 – Potassium, sodium, barium, calcium and magnesium were discovered by Sir Humphry Davy using electrolysis,1821 – Lithium was discovered by the English chemist William Thomas Brande, who obtained it by electrolysis of lithium oxide. 1833 – Michael Faraday develops his two laws of electrolysis, and provides an explanation of his laws. 1875 – Paul Émile Lecoq de Boisbaudran discovered gallium using electrolysis,1886 – Fluorine was discovered by Henri Moissan using electrolysis. The main components required to achieve electrolysis are, An electrolyte, a substance, frequently an ion-conducting polymer that contains free ions, if the ions are not mobile, as in a solid salt then electrolysis cannot occur. A direct current electrical supply, provides the necessary to create or discharge the ions in the electrolyte. Electric current is carried by electrons in the external circuit, two electrodes, electrical conductors that provide the physical interface between the electrolyte and the electrical circuit that provides the energy. Electrodes of metal, graphite and semiconductor material are widely used, choice of suitable electrode depends on chemical reactivity between the electrode and electrolyte and manufacturing cost. The key process of electrolysis is the interchange of atoms and ions by the removal or addition of electrons from the external circuit, the desired products of electrolysis are often in a different physical state from the electrolyte and can be removed by some physical processes. For example, in the electrolysis of brine to produce hydrogen and chlorine and these gaseous products bubble from the electrolyte and are collected. Each electrode attracts ions that are of the opposite charge, positively charged ions move towards the electron-providing cathode. Negatively charged ions move towards the electron-extracting anode, in this process electrons are either absorbed or released. Neutral atoms gain or lose electrons and become charged ions that pass into the electrolyte. The formation of uncharged atoms from ions is called discharging, when an ion gains or loses enough electrons to become uncharged atoms, the newly formed atoms separate from the electrolyte. Positive metal ions like Cu++ deposit onto the cathode in a layer, the terms for this are electroplating, electrowinning, and electrorefining
19.
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
20.
Mint (facility)
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A mint is an industrial facility which manufactures coins that can be used in currency. The history of mints correlates closely with the history of coins, in the beginning, hammered coinage or cast coinage were the chief means of coin minting, with resulting production runs numbering as little as the hundreds or thousands. In modern mints, coin dies are manufactured in large numbers, with the mass production of currency, the production cost is weighed when minting coins. For example, it costs the United States Mint much less than 25 cents to make a quarter, metals were well suited to represent wealth, owing to their great intrinsic value and their durability, divisibility and rarity. The first mint was established in Lydia in the 7th century BC, for coining gold, silver. The Lydian innovation of manufacturing coins under the authority of the spread to neighboring Greece. Some of the earliest Greek mints were within city-states on Greek islands such as Crete, at about the same time, coins and mints appeared independently in China and spread to Korea and Japan. The manufacture of coins in the Roman Empire, dating from about the 4th century BC, the origin of the word mint is ascribed to the manufacture of silver coin at Rome in 269 BC at the temple of Juno Moneta. This goddess became the personification of money, and her name was applied both to money and to its place of manufacture, Roman mints were spread widely across the Empire, and were sometimes used for propaganda purposes. The populace often learned of a new Roman Emperor when coins appeared with the new Emperors portrait, Ancient coins were made by casting in moulds or by striking between engraved dies. The Romans cast their larger copper coins in clay moulds carrying distinctive markings, not because they knew nothing of striking, casting is now used only by counterfeiters. The most ancient coins were cast in bulletshaped or conical moulds, the blank or unmarked piece of metal was placed on a small anvil, and the die was held in position with tongs. The reverse or lower side of the received a rectangular mark made by the sharp edges of the little anvil. Subsequently the anvil was marked in ways, and decorated with letters and figures of beasts. The spherical blanks soon gave place to lenticular-shaped ones, the blank was made red-hot and struck between cold dies. One blow was usually insufficient, and the method was similar to that used in striking medals in high relief. With the substitution of iron for bronze as the material for dies, about 300 AD, in the Middle Ages bars of metal were cast and hammered out on an anvil. Portions of the sheets were then cut out with shears
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Coin
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A coin is a small, flat, round piece of metal or plastic used primarily as a medium of exchange or legal tender. They are standardized in weight, and produced in quantities at a mint in order to facilitate trade. They are most often issued by a government, Coins are usually metal or alloy, or sometimes made of synthetic materials. Coins made of metal are stored in large quantities as bullion coins. Other coins are used as money in transactions, circulating alongside banknotes. Usually the highest value coin in circulation is less than the lowest-value note. In the last hundred years, the value of circulation coins has occasionally been lower than the value of the metal they contain. Exceptions to the rule of face value being higher than content value also occur for some bullion coins made of copper, silver, or gold, while the Eagle, Maple Leaf, and Sovereign coins have nominal face values, the Krugerrand does not. The first coins were developed independently in Iron Age Anatolia and Archaic Greece, India, Coins spread rapidly in the 6th and 5th centuries BCE, throughout Greece and Persia, and further to the Balkans. Standardized Roman currency was used throughout the Roman Empire, important Roman gold and silver coins were continued into the Middle Ages. Fiat money first arose in medieval China, with the paper money. Early paper money was introduced in Europe in the later Middle Ages, the penny was minted as a silver coin until the 17th century. The first circulating United States coins were cents, produced in 1793, Coins were an evolution of currency systems of the Late Bronze Age, where standard-sized ingots, and tokens such as knife money, were used to store and transfer value. In the late Chinese Bronze Age, standardized cast tokens were made and these were replicas in bronze of earlier Chinese currency, cowrie shells, so they were named Bronze Shell. According to Aristotle and Pollux, the first issuer of coins was Hermodike of Kyme The earliest coins are associated with Iron Age Anatolia. Early electrum coins were not standardized in weight, and in their earliest stage may have been ritual objects, such as badges or medals, issued by priests. The first Lydian coins were made of electrum, a naturally occurring alloy of silver, most of the early Lydian coins include no writing, only an image of a symbolic animal. Anatolian Artemis was the Πὀτνια Θηρῶν, whose symbol was the stag, a small percentage of early Lydian/Greek coins have a legend
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Silver
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Silver is a metallic element with symbol Ag and atomic number 47. The symbol Ag stems from Latin argentum, derived from the Greek ὰργὀς, a soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is found in the Earths crust in the pure, free form, as an alloy with gold and other metals. Most silver is produced as a byproduct of copper, gold, lead, Silver is more abundant than gold, but it is much less abundant as a native metal. Its purity is measured on a per mille basis, a 94%-pure alloy is described as 0.940 fine. As one of the seven metals of antiquity, silver has had a role in most human cultures. Silver has long valued as a precious metal. Silver metal is used in many premodern monetary systems in bullion coins, Silver is used in numerous applications other than currency, such as solar panels, water filtration, jewelry, ornaments, high-value tableware and utensils, and as an investment medium. Silver is used industrially in electrical contacts and conductors, in specialized mirrors, window coatings, Silver compounds are used in photographic film and X-rays. Dilute silver nitrate solutions and other compounds are used as disinfectants and microbiocides, added to bandages and wound-dressings, catheters. Silver is similar in its physical and chemical properties to its two neighbours in group 11 of the periodic table, copper and gold. This distinctive electron configuration, with an electron in the highest occupied s subshell over a filled d subshell. Silver is a soft, ductile and malleable transition metal. Silver crystallizes in a cubic lattice with bulk coordination number 12. Unlike metals with incomplete d-shells, metallic bonds in silver are lacking a covalent character and are relatively weak and this observation explains the low hardness and high ductility of single crystals of silver. Silver has a brilliant white metallic luster that can take a polish. Protected silver has greater optical reflectivity than aluminium at all wavelengths longer than ~450 nm, at wavelengths shorter than 450 nm, silvers reflectivity is inferior to that of aluminium and drops to zero near 310 nm. The electrical conductivity of silver is the greatest of all metals, greater even than copper, during World War II in the US,13540 tons of silver were used in electromagnets for enriching uranium, mainly because of the wartime shortage of copper
23.
Cupro-nickel
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Cupronickel is an alloy of copper that contains nickel and strengthening elements, such as iron and manganese. Despite its high content, cupronickel is silver in colour. Cupronickel is highly resistant to corrosion in seawater because its potential is adjusted to be neutral with regard to seawater. Another common use of cupronickel is in silver-coloured modern-circulated coins, a typical mix is 75% copper, 25% nickel, and a trace amount of manganese. In the past, true silver coins were debased with cupronickel, Cupronickel alloys are used for marine applications due to their resistance to seawater corrosion, good fabricability, and their effectiveness in lowering macrofouling levels. Alloys ranging in composition from 90% Cu–10% Ni to 70% Cu–30% Ni are commonly specified in heat exchanger or condenser tubes in a variety of marine applications. Desalination plants, Cupronickel alloys are used in brine heaters, heat rejection and recovery, offshore oil and gas platforms and processing and FPSO vessels, Cupronickel alloys are used in systems and splash zone sheathings. Power generation, Cupronickel alloys are used in steam turbine condensers, oil coolers, auxiliary cooling systems and high pressure pre-heaters at nuclear, seawater system design, Cupronickel alloys are used in tubular heat exchangers and condensers, piping and high pressure systems. Seawater system components, Cupronickel alloys are used in condenser and heat exchanger tubes, tubesheets, piping, fittings, pumps, in Europe, Switzerland pioneered the nickel billon coinage in 1850, with the addition of silver. In 1968, Switzerland adopted the far cheaper 75,25 copper to nickel ratio then being used by the Belgians, the United States, and Germany. From 1947 to 2012, all “silver” coinage in the UK was made from cupronickel, prior to these dates, both denominations had been made only in silver in the United States. Cupronickel is the cladding on either side of United States half-dollars since 1971, currently, some circulating coins, such as the United States Jefferson nickel, the Swiss franc, and the South Korean 500 and 100 won are made of solid cupronickel. Single-core thermocouple cables use a single pair of thermocouple conductors such as iron-constantan. These have the element of constantan or nickel-chromium alloy within a sheath of copper. Cupronickel is used in cryogenic applications, beginning around the turn of the 20th century, bullet jackets were commonly made from this material. It was soon replaced with gilding metal to reduce fouling in the bore. Currently, cupronickel remains the basic material for silver-plated cutlery and it is commonly used for mechanical and electrical equipment, medical equipment, zippers, jewelry items, and as material for strings for string instruments. Fender Musical Instruments used CuNiFe magnets in their Wide Range Humbucker pickup for various Telecaster and Starcaster guitars during the 1970s, for high-quality cylinder locks and locking systems, cylinder cores are made from wear-resistant cupronickel
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Brass
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Brass is a metal alloy made of copper and zinc, the proportions of zinc and copper can be varied to create a range of brasses with varying properties. It is an alloy, atoms of the two constituents may replace each other within the same crystal structure. By comparison, bronze is principally an alloy of copper and tin, however, bronze and brass may also include small proportions of a range of other elements including arsenic, phosphorus, aluminium, manganese, and silicon. The term is applied to a variety of brasses. Modern practice in museums and archaeology increasingly avoids both terms for objects in favour of the all-embracing copper alloy. It is also used in zippers, Brass is often used in situations in which it is important that sparks not be struck, such as in fittings and tools used near flammable or explosive materials. Brass has higher malleability than bronze or zinc, the relatively low melting point of brass and its flow characteristics make it a relatively easy material to cast. By varying the proportions of copper and zinc, the properties of the brass can be changed, allowing hard, the density of brass is 8.4 to 8.73 grams per cubic centimetre. Today, almost 90% of all alloys are recycled. Because brass is not ferromagnetic, it can be separated from ferrous scrap by passing the scrap near a powerful magnet, Brass scrap is collected and transported to the foundry where it is melted and recast into billets. Billets are heated and extruded into the form and size. The general softness of brass means that it can often be machined without the use of cutting fluid, aluminium makes brass stronger and more corrosion-resistant. Aluminium also causes a highly beneficial hard layer of oxide to be formed on the surface that is thin, transparent. Tin has an effect and finds its use especially in seawater applications. Combinations of iron, aluminium, silicon and manganese make brass wear and tear resistant, to enhance the machinability of brass, lead is often added in concentrations of around 2%. Since lead has a melting point than the other constituents of the brass. The pattern the globules form on the surface of the brass increases the available surface area which in turn affects the degree of leaching. In addition, cutting operations can smear the lead globules over the surface and these effects can lead to significant lead leaching from brasses of comparatively low lead content
25.
Perth Mint
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The Perth Mint is Australias official bullion mint and wholly owned by the Government of Western Australia. Along with the Royal Australian Mint, which produces coins of the Australian dollar for circulation, after the foundation stone was laid in 1896 by Sir John Forrest, the Mint opened on 20 June 1899. At that time, Western Australias population was growing rapidly due largely to the discovery of gold deposits in Coolgardie, Kalgoorlie. Although Federation occurred in 1901, the Mint remained under the jurisdiction of Great Britain until 1 July 1970, when it became a statutory authority of the Government of Western Australia. Between 1899 and 1931, the Perth Mint struck more than 106 million gold sovereigns and nearly 735,000 half-sovereigns for use as currency in Australia, the Mint stopped making gold sovereigns when Britain abandoned the gold standard in 1931. Nevertheless, the refinery remained busy as staff turned their skills to making fine gold bullion bars, but it was not long before the Mint was involved again in the production of coins. During World War II, the Perth Mint began minting the Australian coinage from base metals, up until the end of 1983, the Perth Mint also manufactured much of Australias lower-denomination coin currency. The Perth Mint achieved arguably the purest of all gold in 1957 when the mint produced a 13-troy-ounce proof plate of almost six nines -999.999 parts of gold per thousand. The Royal Mint was so impressed that it ordered some of the gold as the benchmark for its own standards, the Mints new direction was formalised in 1987 with the creation of Gold Corporation by a State Act of Parliament. Prime Minister Bob Hawke launched the Australian Nugget Gold Coins Series in 1987, the first days trading yielded sales of 155,000 ounces of gold worth $103 million, well above the sales target of 130,000 ounces to the end of June. Today, the Perth Mint is a member of an group of world mints whose pure gold, silver. Like the Australian Nugget, its Australian Kookaburra Silver Coin Series and Australian Lunar Gold, up to 2000, the Mints refined gold output totalled 4,500 tonnes, representing 3. 25% of the total weight of gold produced by humankind. This is about the current holdings of gold bullion in the United States Mints Fort Knox Bullion Depository, in 2003, the Perth Mint officially opened an 8,400 square metre state-of-the-art manufacturing facility next door to its original limestone building. Dominating the Mints heritage precinct, these two important buildings are powerful symbols of more than 100 years of minting excellence in Western Australia. In October 2011, the Perth Mint created the worlds largest, heaviest and most valuable gold coin, the coin is approximately 80 centimetres in diameter and 12 centimetres thick, and made of 1,012 kilograms of 99. 99% pure gold. It features a red kangaroo on the front of the coin and it is legal tender in Australia with face value A$1 million, but at the time of minting it was valued at A$53.5 million. Today, the Mint continues to provide refining and other services to the industry and manufactures many coin related numismatic items for investors
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Wayback Machine
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The Internet Archive launched the Wayback Machine in October 2001. It was set up by Brewster Kahle and Bruce Gilliat, and is maintained with content from Alexa Internet, the service enables users to see archived versions of web pages across time, which the archive calls a three dimensional index. Since 1996, the Wayback Machine has been archiving cached pages of websites onto its large cluster of Linux nodes and it revisits sites every few weeks or months and archives a new version. Sites can also be captured on the fly by visitors who enter the sites URL into a search box, the intent is to capture and archive content that otherwise would be lost whenever a site is changed or closed down. The overall vision of the machines creators is to archive the entire Internet, the name Wayback Machine was chosen as a reference to the WABAC machine, a time-traveling device used by the characters Mr. Peabody and Sherman in The Rocky and Bullwinkle Show, an animated cartoon. These crawlers also respect the robots exclusion standard for websites whose owners opt for them not to appear in search results or be cached, to overcome inconsistencies in partially cached websites, Archive-It. Information had been kept on digital tape for five years, with Kahle occasionally allowing researchers, when the archive reached its fifth anniversary, it was unveiled and opened to the public in a ceremony at the University of California, Berkeley. Snapshots usually become more than six months after they are archived or, in some cases, even later. The frequency of snapshots is variable, so not all tracked website updates are recorded, Sometimes there are intervals of several weeks or years between snapshots. After August 2008 sites had to be listed on the Open Directory in order to be included. As of 2009, the Wayback Machine contained approximately three petabytes of data and was growing at a rate of 100 terabytes each month, the growth rate reported in 2003 was 12 terabytes/month, the data is stored on PetaBox rack systems manufactured by Capricorn Technologies. In 2009, the Internet Archive migrated its customized storage architecture to Sun Open Storage, in 2011 a new, improved version of the Wayback Machine, with an updated interface and fresher index of archived content, was made available for public testing. The index driving the classic Wayback Machine only has a bit of material past 2008. In January 2013, the company announced a ground-breaking milestone of 240 billion URLs, in October 2013, the company announced the Save a Page feature which allows any Internet user to archive the contents of a URL. This became a threat of abuse by the service for hosting malicious binaries, as of December 2014, the Wayback Machine contained almost nine petabytes of data and was growing at a rate of about 20 terabytes each week. Between October 2013 and March 2015 the websites global Alexa rank changed from 162 to 208, in a 2009 case, Netbula, LLC v. Chordiant Software Inc. defendant Chordiant filed a motion to compel Netbula to disable the robots. Netbula objected to the motion on the ground that defendants were asking to alter Netbulas website, in an October 2004 case, Telewizja Polska USA, Inc. v. Echostar Satellite, No.02 C3293,65 Fed. 673, a litigant attempted to use the Wayback Machine archives as a source of admissible evidence, Telewizja Polska is the provider of TVP Polonia and EchoStar operates the Dish Network
