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29-547: Sphalerite is a sulfide mineral with the chemical formula ( Zn , Fe ) S . It is the most important ore of zinc . Sphalerite is found in a variety of deposit types, but it is primarily in sedimentary exhalative , Mississippi-Valley type , and volcanogenic massive sulfide deposits. It is found in association with galena , chalcopyrite , pyrite (and other sulfides ), calcite , dolomite , quartz , rhodochrosite , and fluorite . German geologist Ernst Friedrich Glocker discovered sphalerite in 1847, naming it based on

58-465: A characteristic triboluminescence of yellow-orange. Typically, specimens cut into end-slabs are ideal for displaying this property. Gemmy, colorless to pale green sphalerite from Franklin, New Jersey (see Franklin Furnace ), are highly fluorescent orange and/or blue under longwave ultraviolet light and are known as cleiophane , an almost pure ZnS variety. Cleiophane contains less than 0.1% of iron in

87-569: A hardness on the Mohs scale. However, hardness can make it difficult to determine if the substance is a mixture of other substances or if it may be misleading or meaningless. For example, some sources have assigned a Mohs hardness of 6 or 7 to granite but it is a rock made of several minerals, each with its own Mohs hardness (e.g. topaz-rich granite contains: topaz — Mohs 8, quartz — Mohs 7, orthoclase — Mohs 6, plagioclase — Mohs 6–6.5, mica — Mohs 2–4). Despite its lack of precision,

116-506: A new hierarchical scheme (Mills et al., 2009). This list uses the Classification of Nickel–Strunz ( mindat.org , 10 ed, pending publication). [REDACTED] Media related to Sulfide minerals at Wikimedia Commons Mohs scale of mineral hardness The Mohs scale ( / m oʊ z / MOHZ ) of mineral hardness is a qualitative ordinal scale , from 1 to 10, characterizing scratch resistance of minerals through

145-545: A ternary compound between the binary endpoints ZnS and FeS with composition Zn x Fe (1-x) S, where x can range from 1 (pure ZnS) to 0.6. All natural sphalerite contains concentrations of various impurities, which generally substitute for zinc in the cation position in the lattice; the most common cation impurities are cadmium , mercury and manganese , but gallium , germanium and indium may also be present in relatively high concentrations (hundreds to thousands of ppm). Cadmium can replace up to 1% of zinc and manganese

174-474: Is a semiconductor, but transitions to a conductor as the iron content increases. It has a hardness of 3.5 to 4 on the Mohs scale of mineral hardness . It can be distinguished from similar minerals by its perfect cleavage, its distinctive resinous luster, and the reddish-brown streak of the darker varieties. Pure zinc sulfide is a wide-bandgap semiconductor , with bandgap of about 3.54 electron volts, which makes

203-490: Is an ordinal scale . For example, corundum (9) is twice as hard as topaz (8), but diamond (10) is four times as hard as corundum. The table below shows the comparison with the absolute hardness measured by a sclerometer , with images of the reference minerals in the rightmost column. Below is a table of more materials by Mohs scale. Some of them have a hardness between two of the Mohs scale reference minerals. Some solid substances that are not minerals have been assigned

232-446: Is generally found in sphalerite with high iron abundances. Sulfur in the anion position can be substituted for by selenium and tellurium . The abundances of these impurities are controlled by the conditions under which the sphalerite formed; formation temperature, pressure, element availability and fluid composition are important controls. Sphalerite possesses perfect dodecahedral cleavage , having six cleavage planes. In pure form, it

261-462: Is of great antiquity, having been mentioned by Theophrastus in his treatise On Stones , c.  300 BC , followed by Pliny the Elder in his Naturalis Historia , c.  AD 77 . The Mohs scale is useful for identification of minerals in the field , but is not an accurate predictor of how well materials endure in an industrial setting. The Mohs scale of mineral hardness is based on

290-415: Is pure ZnS to 2.50 when there is 40% iron content. Sphalerite is isotropic under cross-polarized light, however sphalerite can experience birefringence if intergrown with its polymorph wurtzite; the birefringence can increase from 0 (0% wurtzite) up to 0.022 (100% wurtzite). Depending on the impurities, sphalerite will fluoresce under ultraviolet light. Sphalerite can be triboluminescent . Sphalerite has

319-1055: Is termed ruby blende or ruby zinc, whereas dark colored sphalerite is termed black-jack. Sphalerite is amongst the most common sulfide minerals, and it is found worldwide and in a variety of deposit types. The reason for the wide distribution of sphalerite is that it appears in many types of deposits; it is found in skarns , hydrothermal deposits , sedimentary beds, volcanogenic massive sulfide deposits (VMS), Mississippi-valley type deposits (MVT), granite and coal . Approximately 50% of zinc (from sphalerite) and lead comes from Sedimentary exhalative (SEDEX) deposits, which are stratiform Pb-Zn sulfides that form at seafloor vents. The metals precipitate from hydrothermal fluids and are hosted by shales, carbonates and organic-rich siltstones in back-arc basins and failed continental rifts. The main ore minerals in SEDEX deposits are sphalerite, galena, pyrite, pyrrhotite and marcasite , with minor sulfosalts such as tetrahedrite - freibergite and boulangerite ;

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348-825: The Canadian arctic, Mississippi River in the United States , Pine Point in Northwest Territories, and Admiral Bay in Australia. Volcanogenic massive sulfide (VMS) deposits can be Cu-Zn- or Zn-Pb-Cu-rich, and accounts for 25% of Zn in reserves. There are various types of VMS deposits with a range of regional contexts and host rock compositions; a common characteristic is that they are all hosted by submarine volcanic rocks. They form from metals such as copper and zinc being transferred by hydrothermal fluids (modified seawater) which leach them from volcanic rocks in

377-518: The Greek word sphaleros , meaning "deceiving", due to the difficulty of identifying the mineral. In addition to zinc, sphalerite is an ore of cadmium , gallium , germanium , and indium . Miners have been known to refer to sphalerite as zinc blende , black-jack , and ruby blende . Marmatite is an opaque black variety with a high iron content. Sphalerite crystallizes in the face-centered cubic zincblende crystal structure, which named after

406-464: The Mohs scale can create microscopic, non-elastic dislocations on materials that have a higher Mohs number. While these microscopic dislocations are permanent and sometimes detrimental to the harder material's structural integrity, they are not considered "scratches" for the determination of a Mohs scale number. Each of the ten hardness values in the Mohs scale is represented by a reference mineral , most of which are widespread in rocks. The Mohs scale

435-406: The Mohs scale is relevant for field geologists, who use it to roughly identify minerals using scratch kits. The Mohs scale hardness of minerals can be commonly found in reference sheets. Mohs hardness is useful in milling . It allows the assessment of which type of mill and grinding medium will best reduce a given product whose hardness is known. Electronic manufacturers use the scale for testing

464-529: The United States, Russia, Mexico , Germany , Australia, Canada , China , Ireland , Peru , Kazakhstan and England . Sources of high quality crystals include: Sphalerite is an important ore of zinc; around 95% of all primary zinc is extracted from sphalerite ore. However, due to its variable trace element content, sphalerite is also an important source of several other metals such as cadmium, gallium, germanium, and indium which replace zinc. The ore

493-625: The ability of harder material to scratch softer material. The scale was introduced in 1812 by the German geologist and mineralogist Friedrich Mohs , in his book Versuch einer Elementar-Methode zur naturhistorischen Bestimmung und Erkennung der Fossilien (English: Attempt at an elementary method for the natural-historical determination and recognition of fossils); it is one of several definitions of hardness in materials science , some of which are more quantitative. The method of comparing hardness by observing which minerals can scratch others

522-424: The ability of one natural sample of mineral to visibly scratch another mineral. Minerals are chemically pure solids found in nature. Rocks are mixtures of one or more minerals. Diamond was the hardest known naturally occurring mineral when the scale was designed, and defines the top of the scale, arbitrarily set at 10. The hardness of a material is measured against the scale by finding the hardest material that

551-544: The cementation process of brass in Northern China during the 12th–13th century CE ( Jin Dynasty ). Besides brass, the zinc in sphalerite can also be used to produce certain types of bronze; bronze is dominantly copper which is alloyed with other metals such as tin, zinc, lead, nickel, iron and arsenic. Sulfide mineral Common or important examples include: Sulfarsenides: Sulfosalts: IMA -CNMNC proposes

580-411: The given material can scratch, or the softest material that can scratch the given material. For example, if some material is scratched by apatite but not by fluorite , its hardness on the Mohs scale would be between 4 and 5. Technically, "scratching" a material for the purposes of the Mohs scale means creating non- elastic dislocations visible to the naked eye. Frequently, materials that are lower on

609-413: The mineral. This structure is a member of the hextetrahedral crystal class ( space group F 4 3m). In the crystal structure, both the sulfur and the zinc or iron ions occupy the points of a face-centered cubic lattice, with the two lattices displaced from each other such that the zinc and iron are tetrahedrally coordinated to the sulfur ions, and vice versa . Minerals similar to sphalerite include those in

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638-665: The oceanic crust; the metal-saturated fluid rises through fractures and faults to the surface, where it cools and deposits the metals as a VMS deposit. The most abundant ore minerals are pyrite, chalcopyrite, sphalerite and pyrrhotite. Mines that contain VMS deposits include Kidd Creek in Ontario, Urals in Russia , Troodos in Cyprus , and Besshi in Japan . The top producers of sphalerite include

667-440: The pure material transparent in the visible spectrum. Increasing iron content will make the material opaque, while various impurities can give the crystal a variety of colors. In thin section, sphalerite exhibits very high positive relief and appears colorless to pale yellow or brown, with no pleochroism . The refractive index of sphalerite (as measured via sodium light, average wavelength 589.3 nm) ranges from 2.37 when it

696-510: The replacement of carbonate host rocks such as dolostone and limestone by ore minerals; they are located in platforms and foreland thrust belts. Furthermore, they are stratabound, typically Phanerozoic in age and epigenetic (form after the lithification of the carbonate host rocks). The ore minerals are the same as SEDEX deposits: sphalerite, galena, pyrite, pyrrhotite and marcasite, with minor sulfosalts. Mines that contain MVT deposits include Polaris in

725-729: The sphalerite crystal structure. Marmatite or christophite is an opaque black variety of sphalerite and its coloring is due to high quantities of iron, which can reach up to 25%; marmatite is named after Marmato mining district in Colombia and christophite is named for the St. Christoph mine in Breitenbrunn , Saxony . Both marmatite and cleiophane are not recognized by the International Mineralogical Association (IMA). Red, orange or brownish-red sphalerite

754-427: The sphalerite group, consisting of sphalerite, colaradoite , hawleyite , metacinnabar , stilleite and tiemannite . The structure is closely related to the structure of diamond . The hexagonal polymorph of sphalerite is wurtzite , and the trigonal polymorph is matraite. Wurtzite is the higher temperature polymorph, stable at temperatures above 1,020 °C (1,870 °F). The lattice constant for zinc sulfide in

783-717: The zinc + lead grade typically ranges between 10 and 20%. Important SEDEX mines are Red Dog in Alaska , Sullivan Mine in British Columbia , Mount Isa and Broken Hill in Australia and Mehdiabad in Iran . Similar to SEDEX, Mississippi-Valley type (MVT) deposits are also a Pb-Zn deposit which contains sphalerite. However, they only account for 15–20% of zinc and lead, are 25% smaller in tonnage than SEDEX deposits and have lower grades of 5–10% Pb + Zn. MVT deposits form from

812-429: The zinc blende crystal structure is 0.541 nm . Sphalerite has been found as a pseudomorph , taking the crystal structure of galena , tetrahedrite , barite and calcite . Sphalerite can have Spinel Law twins, where the twin axis is [111]. The chemical formula of sphalerite is (Zn,Fe)S ; the iron content generally increases with increasing formation temperature and can reach up to 40%. The material can be considered

841-513: Was originally called blende by miners (from German blind or deceiving ) because it resembles galena but yields no lead. The zinc in sphalerite is used to produce brass , an alloy of copper with 3–45% zinc. Major element alloy compositions of brass objects provide evidence that sphalerite was being used to produce brass by the Islamic as far back as the medieval ages between the 7th and 16th century CE. Sphalerite may have also been used during

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