"addition the oxidation of those sulfide deposits which contained gold, often resulted in the concentration of gold in the iron oxide and quartz of the gossans. Goldbearing limonite gossans were productively mined in the Shasta County, California mining district. Similar deposits were mined near Rio Tinto in Spain and Mount Morgan in Australia. In the Dahlonega gold belt in Lumpkin County, Georgia gold was mined from limonite-rich lateritic or saprolite soil. The gold of the primary veins was concentrated into the limonites of the deeply weathered rocks. In another example the deeply weathered iron formations of Brazil served to concentrate"
"and silicate types. Limonite type laterites (or oxide type) are highly enriched in iron due to very strong leaching of magnesium and silica. They consist largely of goethite and contain 1-2% nickel incorporated in goethite. Absence of the limonite zone in the ore deposits is due to erosion. Silicate type (or saprolite type) nickel ore formed beneath the limonite zone. It contains generally 1.5-2.5% nickel and consists largely of Mg-depleted serpentine in which nickel is incorporated. In pockets and fissures of the serpentinite rock green garnierite can be present in minor quantities, but with high nickel contents - mostly 20-40%."
"Carminite Carminite (PbFe(AsO)(OH)) is an anhydrous arsenate mineral containing hydroxyl. It is a rare secondary mineral that is structurally related to palermoite (LiSrAl(PO)(OH)). Sewardite (CaFe(AsO)(OH)) is an analogue of carminite, with calcium in sewardite in place of the lead in carminite. Mawbyite is a dimorph (same formula, different structure) of carminite; mawbyite is monoclinic and carminite is orthorhombic. It has a molar mass of 639.87 g. It was discovered in 1850 and named for the characteristic carmine colour. Carminite belongs to the orthorhombic crystal class (2/m 2/m 2/m) and has space group C ccm or C cc2. The structure consists"
"with cerussite, anglesite and plumbojarosite. It is almost always intimately associated with arseniosiderite and dussertite. Carminite Carminite (PbFe(AsO)(OH)) is an anhydrous arsenate mineral containing hydroxyl. It is a rare secondary mineral that is structurally related to palermoite (LiSrAl(PO)(OH)). Sewardite (CaFe(AsO)(OH)) is an analogue of carminite, with calcium in sewardite in place of the lead in carminite. Mawbyite is a dimorph (same formula, different structure) of carminite; mawbyite is monoclinic and carminite is orthorhombic. It has a molar mass of 639.87 g. It was discovered in 1850 and named for the characteristic carmine colour. Carminite belongs to the orthorhombic crystal class"
"orebody. The minerals making most of the orebody are realgar, orpiment, As-bearing pyrite and marcasite. The deposit was mined extensively between 1880 and 1908. Antimony, arsenic and thallium were produced during that period. Pyrite, stibnite, orpiment and realgar are the main minerals forming the ore. Lorandite – a thallium arsenic sulfosalt mineral with formula TlAsS – is the main thallium mineral in the deposit. Several other thallium minerals have been discovered in the mine over the years, for example, jankovićite (TlSb(As,Sb)S, fangite (TlAsS) and bernardite (TI(Sb,As)S). LORandite EXperiment (LOREX) is using lorandite from the ore deposit to determine the solar"
"Peridot Peridot ( or ) is gem-quality olivine, which is a silicate mineral with the formula of (Mg, Fe)SiO. As peridot is the magnesium-rich variety of olivine (forsterite), the formula approaches MgSiO. The origin of the name ""peridot"" is uncertain. The ""Oxford English Dictionary"" suggests an alteration of Anglo–Norman ""pedoretés"" (classical Latin ""pæderot""-), a kind of opal, rather than the Arabic word ""faridat"", meaning ""gem"". The Middle English Dictionary's entry on ""peridot"" includes several variations : ""peridod"", ""peritot"", ""pelidod"" and ""pilidod"" – other variants substitute ""y"" for the ""i""s seen here. The earliest use in England is in the register"
"deposit near Mae Sod in western Thailand; Sardinia; Nerchinsk, Siberia; Cave del Predil, Italy; Bleiberg, Carinthia, Austria; Matlock, Derbyshire, England. Hemimorphite Hemimorphite, is Zn(SiO)(OH)·HO, a component of calamine. It is a sorosilicate mineral which has been historically mined from the upper parts of zinc and lead ores, chiefly associated with smithsonite, ZnCO. They were assumed to be the same mineral and both were classed under the same name of calamine. In the second half of the 18th century it was discovered that these two different minerals were both present in calamine. They closely resemble each other. The silicate was the"
"resulting from exceptionally bulky ligands such as the tricoordinate [Pr{N(SiMe)}]. There are also a few mixed oxides and fluorides involving praseodymium(IV), but it does not have an appreciable coordination chemistry in this oxidation state like its neighbour cerium. In 1751, the Swedish mineralogist Axel Fredrik Cronstedt discovered a heavy mineral from the mine at Bastnäs, later named cerite. Thirty years later, the fifteen-year-old Vilhelm Hisinger, from the family owning the mine, sent a sample of it to Carl Scheele, who did not find any new elements within. In 1803, after Hisinger had become an ironmaster, he returned to the mineral"
"Hemimorphite Hemimorphite, is Zn(SiO)(OH)·HO, a component of calamine. It is a sorosilicate mineral which has been historically mined from the upper parts of zinc and lead ores, chiefly associated with smithsonite, ZnCO. They were assumed to be the same mineral and both were classed under the same name of calamine. In the second half of the 18th century it was discovered that these two different minerals were both present in calamine. They closely resemble each other. The silicate was the rarer of the two, and was named hemimorphite, because of the hemimorph development of its crystals. This unusual form, which"
"Lepidolite Lepidolite is a lilac-gray or rose-colored member of the mica group of minerals with formula K(Li,Al,Rb)(Al,Si)O(F,OH). It is the most abundant lithium-bearing mineral and is a secondary source of this metal. It is a phyllosilicate mineral and a member of the polylithionite-trilithionite series. It is associated with other lithium-bearing minerals like spodumene in pegmatite bodies. It is one of the major sources of the rare alkali metals rubidium and caesium. In 1861, Robert Bunsen and Gustav Kirchhoff extracted of lepidolite and yielded a few grams of rubidium salts for analysis, and therefore discovered the new element rubidium. It occurs"
"Siderotil Siderotil is an iron(II) sulfate hydrate mineral with formula: FeSO·5HO which forms by the dehydration of melanterite. Copper commonly occurs substituting for iron in the structure. It typically occurs as fibrous or powdery encrustations, but may also occur as acicular triclinic crystals. It was first described in 1891 for an occurrence in the Idrija Mine, Idrija, Slovenia. Its name derives from the Greek ""sideros"" (iron) and ""tilos"" (fiber) in reference to its iron content and typical fibrous form. However, the material at the Idrija location may not be siderotil, but the mineral has been authenticated from a wide variety"
"to discover a second element: the element he thought was aluminium (alumina) was in fact beryllium (beryllia), an element that was not officially identified until 1798. Gadolinite and euxenite are quite abundant and are future sources of yttrium sub group rare earths. At present, these elements are recovered from monazite concentrates (after recovery of ceria sub-group metals). Gadolinite Gadolinite, sometimes known as ytterbite, is a silicate mineral consisting principally of the silicates of cerium, lanthanum, neodymium, yttrium, beryllium, and iron with the formula (Ce,La,Nd,Y)FeBeSiO. It is called gadolinite-(Ce) or gadolinite-(Y), depending on the prominent composing element (Y if yttrium predominates,"
"Gedrite Gedrite is a crystal belonging to the orthorhombic ferromagnesian subgroup of the amphibole supergroup of the double chain inosilicate minerals with the ideal formula: Mg(MgAl)(SiAl)O(OH) Gedrite is the magnesium (Mg) rich endmember of a solid solution series, with divalent magnesium cations readily replaced with ferrous iron (Fe), leading to the iron rich endmember 'ferrogedrite', with the formula: Fe(FeAl)(SiAl)O(OH). However, pure endmembers are very rare, with often either one of the mentioned cations dominating the composition. Thus, the formula can be written in such a way to express common intermediary gerdite samples: (Mg,Fe)(Mg,Fe)Al(AlSiO)(OH). Divalent manganese (Mn) may substitute for some"
"or chromite ores. Sulfides associated with peridotites form nickel ores and platinoid metals; most of the platinum used in the world today is mined from the Bushveld Igneous Complex in South Africa and the Great Dyke of Zimbabwe. The chromite bands found in peridotites are the world's major source of chromium. Peridotite Peridotite is a dense, coarse-grained igneous rock consisting mostly of the minerals olivine and pyroxene. Peridotite is ultramafic, as the rock contains less than 45% silica (). It is high in magnesium (Mg), reflecting the high proportions of magnesium-rich olivine, with appreciable iron. Peridotite is derived from the"
"Gadolinite Gadolinite, sometimes known as ytterbite, is a silicate mineral consisting principally of the silicates of cerium, lanthanum, neodymium, yttrium, beryllium, and iron with the formula (Ce,La,Nd,Y)FeBeSiO. It is called gadolinite-(Ce) or gadolinite-(Y), depending on the prominent composing element (Y if yttrium predominates, and Ce if cerium). It may contain 35.48% yttria sub-group rare earths, 2.17% ceria earths, as much as to 11.6% BeO, and traces of thorium. It is found in Sweden, Norway, and the US (Texas and Colorado). Gadolinite is fairly rare and typically occurs as well-formed crystals. It is nearly black in color and has a vitreous"
"Seifertite Seifertite is a silicate mineral with the formula SiO and is one of the densest polymorphs of silica. It has only been found in Martian and lunar meteorites, where it is presumably formed from either tridymite or cristobalite – other polymorphs of quartz – as a result of heating during the atmospheric re-entry and impact to the Earth, at an estimated minimal pressure of 35 GPa. It can also be produced in the laboratory by compressing cristobalite in a diamond anvil cell to pressures above 40 GPa. The mineral is named after Friedrich Seifert (born 1941), the founder of"
"Two polymorphs of forsterite are known: wadsleyite (also orthorhombic) and ringwoodite (isometric). Both are mainly known from meteorites. Peridot is the gemstone variety of forsterite olivine. Pure forsterite is composed of magnesium, oxygen and silicon. The chemical formula is MgSiO. Forsterite, fayalite (FeSiO) and tephroite (MnSiO) are the end-members of the olivine solid solution series; other elements such as Ni and Ca substitute for Fe and Mg in olivine, but only in minor proportions in natural occurrences. Other minerals such as monticellite (CaMgSiO), an uncommon calcium-rich mineral, share the olivine structure, but solid solution between olivine and these other minerals"
"Hematite Hematite, also spelled as haematite, is the mineral form of iron(III) oxide (FeO), one of several iron oxides. It is the oldest known iron oxide mineral that has ever formed on earth, and is widespread in rocks and soils. Hematite crystallizes in the rhombohedral lattice system, and it has the same crystal structure as ilmenite and corundum. Hematite and ilmenite form a complete solid solution at temperatures above . Hematite is colored black to steel or silver-gray, brown to reddish brown, or red. It is mined as the main ore of iron. Varieties include ""kidney ore"", ""martite"" (pseudomorphs after"
"nickel to magnesium. Pecoraite is another rare mineral with the same chemical formula as népouite, but a different structure; such minerals are said to be dimorphs of each other, in the same way as graphite is a dimorph of diamond. Népouite, lizardite and pecoraite are all members of the kaolinite-serpentine group. Garnierite is a green nickel ore that formed as a result of weathering of ultramafic rocks, and that occurs in many nickel deposits worldwide. It is a mixture of various nickel and magnesium phyllosilicates (sheet silicates), including népouite. Associated minerals include calcite, chlorite, goethite, halloysite, nontronite, pimelite, quartz, sepiolite,"
"SiO(45–47%), CaO (4.7–6.1%), MnO (0.6–1.3%), MgO (0.3-1%), TiO (0.2–0.5%) and AlO (0.2–1.2%). Whereas magnesium is usually present at about 0.8%, in some samples it had an undetectably low concentration. Pyroxferroite Pyroxferroite (Fe,Ca)SiO is a single chain inosilicate. It is mostly composed of iron, silicon and oxygen, with smaller fractions of calcium and several other metals. Together with armalcolite and tranquillityite, it is one of the three minerals which were discovered on the Moon. It was then found in Lunar and Martian meteorites as well as a mineral in the Earth's crust. Pyroxferroite can also be produced by annealing synthetic clinopyroxene"
"Diorite Diorite () is an intrusive igneous rock composed principally of the silicate minerals plagioclase feldspar (typically andesine), biotite, hornblende, and/or pyroxene. The chemical composition of diorite is intermediate, between that of mafic gabbro and felsic granite. Diorite is usually grey to dark-grey in colour, but it can also be black or bluish-grey, and frequently has a greenish cast. It is distinguished from gabbro on the basis of the composition of the plagioclase species; the plagioclase in diorite is richer in sodium and poorer in calcium. Diorite may contain small amounts of quartz, microcline, and olivine. Zircon, apatite, titanite, magnetite,"
"is crystal lined, irregular, and known for being a source of rare minerals, such as beryllium, that are not normally found in abundance in igneous rocks (https://web.archive.org/web/20091028021704/http://geocities.com/oklahomamgs/London/Pegmatite2.html). While initially found in Gugia, China, its localities have expanded to include Piedmont, Italy, Ehime Prefecture, Japan, Eastern Siberian Region, Russia, and most recently Telemark, Norway (http://www.mindat.org/min-1769.html). Gugiaite is composed of infinite sheets of tetrahedra with Be-Si-Si linkages and interstitial Ca (Hawthorne and Huminicki 2002). As shown in Figure 1, the oxygen atom bonds to a [4]-coordinated high-valence cation, Si, to produce a discontinuous polymerization of tetrahedra linked by interstitial Ca (Hawthorne and"
"olivine is a 310 carat (62 g) specimen in the Smithsonian Museum in Washington, D.C. Peridot olivine is the birthstone for the month of August. Peridot Peridot ( or ) is gem-quality olivine, which is a silicate mineral with the formula of (Mg, Fe)SiO. As peridot is the magnesium-rich variety of olivine (forsterite), the formula approaches MgSiO. The origin of the name ""peridot"" is uncertain. The ""Oxford English Dictionary"" suggests an alteration of Anglo–Norman ""pedoretés"" (classical Latin ""pæderot""-), a kind of opal, rather than the Arabic word ""faridat"", meaning ""gem"". The Middle English Dictionary's entry on ""peridot"" includes several variations"
"Tetrahedrite Tetrahedrite is a copper antimony sulfosalt mineral with formula: . It is the antimony endmember of the continuous solid solution series with arsenic-bearing tennantite. Pure endmembers of the series are seldom if ever seen in nature. Of the two, the antimony rich phase is more common. Other elements also substitute in the structure, most notably iron and zinc, along with less common silver, mercury and lead. Bismuth also substitutes for the antimony site and ""bismuthian tetrahedrite"" or ""annivite"" is a recognized variety. The related, silver dominant, mineral species freibergite, although rare, is notable in that it can contain up"
"of worldwide locations. Siderotil Siderotil is an iron(II) sulfate hydrate mineral with formula: FeSO·5HO which forms by the dehydration of melanterite. Copper commonly occurs substituting for iron in the structure. It typically occurs as fibrous or powdery encrustations, but may also occur as acicular triclinic crystals. It was first described in 1891 for an occurrence in the Idrija Mine, Idrija, Slovenia. Its name derives from the Greek ""sideros"" (iron) and ""tilos"" (fiber) in reference to its iron content and typical fibrous form. However, the material at the Idrija location may not be siderotil, but the mineral has been authenticated from"
"Åkermanite Åkermanite (CaMg[SiO]) is a melilite mineral of the sorosilicate group, containing calcium, magnesium, silicon, and oxygen. It is a product of contact metamorphism of siliceous limestones and dolostones, and rocks of sanidinite facies. Sanidinite facies represent the highest conditions of temperature of contact metamorphism and are characterized by the absence of hydrous minerals. It has a density of 2.944 g/cm. Åkermanite ranks a 5 or 6 on the Mohs scale of mineral hardness, and can be found gray, green, brown, or colorless. It has a white streak and a vitreous or resinous luster. It has a tetragonal crystal system"
"Stony-iron meteorite Stony-iron meteorites or siderolites are meteorites that consist of nearly equal parts of meteoric iron and silicates. This distinguishes them from the stony meteorites, that are mostly silicates, and the iron meteorites, that are mostly meteoric iron. Stony-iron meteorites are all differentiated, meaning that they show signs of alteration. They are therefore achondrites. The stony-irons are divided into mesosiderites and pallasites. Pallasites have a matrix of meteoric iron with embedded silicates (most of it olivine). Mesosiderites are breccias which show signs of metamorphism. The meteoric iron occurs in clasts instead of a matrix. They are in the top"
"as the similarly recovered monazite (which typically contains a few percent of yttrium). Uranium ores from Ontario have occasionally yielded yttrium as a byproduct. Well-known minerals containing cerium, and other LREE, include bastnäsite, monazite, allanite, loparite, ancylite, parisite, lanthanite, chevkinite, cerite, stillwellite, britholite, fluocerite, and cerianite. Monazite (marine sands from Brazil, India, or Australia; rock from South Africa), bastnäsite (from Mountain Pass, California, or several localities in China), and loparite (Kola Peninsula, Russia) have been the principal ores of cerium and the light lanthanides. Enriched deposits of rare-earth elements at the surface of the Earth, carbonatites and pegmatites, are related"
"Cymrite Cymrite is a silicate mineral with the chemical formula BaAlSi(O,OH)·HO. The mineral is named for Cymru, which is the Welsh word for Wales. Cymrite, with perfect cleavage and a monoclinic crystalline system, falls in the silicate group. Silicates are formed of Silicon and Oxygen bonding together to form tetrahedra. The symmetry of Cymrite is classified as having a mirror plane. It has a moderate relief, meaning the contrast between the mineral and the epoxy of a thin section makes cymrite easily visible. The birefringence of the mineral is 0.01. Cymrite, being monoclinic is anisotropic with two optic axes. Cymrite"
"Lorándite Lorándite is a thallium arsenic sulfosalt with the chemical formula: TlAsS. Though rare, it is the most common thallium-bearing mineral. Lorandite occurs in low-temperature hydrothermal associations and in gold and mercury ore deposits. Associated minerals include stibnite, realgar, orpiment, cinnabar, vrbaite, greigite, marcasite, pyrite, tetrahedrite, antimonian sphalerite, arsenic and barite. The mineral is being used for detection of solar neutrino via a certain nuclear reaction involving thallium. It has a monoclinic crystal structure consisting of spiral chains of AsS tetrahedra interconnected by thallium atoms, and can be synthesized in the laboratory. Lorándite was first discovered at the Allchar deposit,"
"Thus, the LORandite EXperiment (LOREX), is running between 2008 and 2010 and is based in one of the largest source of lorandite, the Allchar deposit in southern Macedonia. Lorándite Lorándite is a thallium arsenic sulfosalt with the chemical formula: TlAsS. Though rare, it is the most common thallium-bearing mineral. Lorandite occurs in low-temperature hydrothermal associations and in gold and mercury ore deposits. Associated minerals include stibnite, realgar, orpiment, cinnabar, vrbaite, greigite, marcasite, pyrite, tetrahedrite, antimonian sphalerite, arsenic and barite. The mineral is being used for detection of solar neutrino via a certain nuclear reaction involving thallium. It has a monoclinic"
"Hemihedrite Hemihedrite is a rare lead zinc chromate silicate mineral with formula PbZn(CrO)(SiO)(F,OH). It forms a series with the copper analogue iranite. Hemihedrite was first described in 1967 for occurrences in the Florence lead silver mine in the Ripsey District, Tortilla Mountains, Pinal County, Arizona, US. It was named for the hemihedral morphology of its crystals. It occurs in oxidized veins containing galena, sphalerite and pyrite. Associated secondary minerals include cerussite, phoenicochroite, vauquelinite, willemite, wulfenite, galena, sphalerite, pyrite, tennantite and chalcopyrite. It has been reported from several mining districts in Arizona and one in Nevada. It has also been reported"
"of 4. It has a yellow streak. The mineral is classified under the space group P422 and is tetragonal. Cyrilovite Cyrilovite (NaFe(PO)(OH)·2(HO)) is a hydrous sodium iron phosphate mineral. It is isomorphous and isostructural with wardite, the sodium aluminium counterpart. Cyrilovite is found in granitic pegmatites. It was first discovered in 1953 in a pegmatite at Cyrilov, near Velké Meźiřiči, West Moravia, Czech Republic. The chemical formula of cyrilovite is NaFe(PO)(OH)·2(HO). Parent phosphate minerals, fluorapatite and triplite-zwieselite, were transformed by hydrothermal alteration and weathering to give a complex, microcrystalline intergrowth of secondary phosphate minerals that include cyrilovite. The sequence of"