Bauxite is a sedimentary rock with a relatively high aluminium content. It is the world's main source of aluminium and gallium. Bauxite consists mostly of the aluminium minerals gibbsite (Al(OH)3), boehmite (γ-AlO(OH)) and diaspore (α-AlO(OH)), mixed with the two iron oxides goethite (FeO(OH)) and haematite (Fe2O3), the aluminium clay mineral kaolinite (Al2Si2O5(OH)4) and small amounts of anatase (TiO2) and ilmenite (FeTiO3 or FeO.TiO2). Bauxite appears dull in luster and is reddish-brown, white, or tan.
Beryl ( BERR-əl) is a mineral composed of beryllium aluminium silicate with the chemical formula Be3Al2Si6O18. Well-known varieties of beryl include emerald and aquamarine. Naturally occurring, hexagonal crystals of beryl can be up to several meters in size, but terminated crystals are relatively rare. Pure beryl is colorless, but it is frequently tinted by impurities; possible colors are green, blue, yellow, pink, and red (the rarest). It is an ore source of beryllium.
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.
Muscovite (also known as common mica, isinglass, or potash mica) is a hydrated phyllosilicate mineral of aluminium and potassium with formula KAl2(AlSi3O10)(F,OH)2, or (KF)2(Al2O3)3(SiO2)6(H2O). It has a highly perfect basal cleavage yielding remarkably thin laminae (sheets) which are often highly elastic. Sheets of muscovite 5 meters × 3 meters (16.5 feet × 10 feet) have been found in Nellore, India.
Strontianite (SrCO3) is an important raw material for the extraction of strontium. It is a rare carbonate mineral and one of only a few strontium minerals. It is a member of the aragonite group.
Ilmenite is a titanium-iron oxide mineral with the idealized formula FeTiO
3. It is a weakly magnetic black or steel-gray solid. Ilmenite is the most important ore of titanium and the main source of titanium dioxide, which is used in paints, printing inks, fabrics, plastics, paper, sunscreen, food and cosmetics.
Chalcopyrite ( KAL-kə-PY-ryte, -koh-) is a copper iron sulfide mineral and the most abundant copper ore mineral. It has the chemical formula CuFeS2 and crystallizes in the tetragonal system. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green-tinged black.
Vanadinite is a mineral belonging to the apatite group of phosphates, with the chemical formula Pb5(VO4)3Cl. It is one of the main industrial ores of the metal vanadium and a minor source of lead. A dense, brittle mineral, it is usually found in the form of red hexagonal crystals. It is an uncommon mineral, formed by the oxidation of lead ore deposits such as galena. First discovered in 1801 in Mexico, vanadinite deposits have since been unearthed in South America, Europe, Africa, and North America.
Wulfenite is a lead molybdate mineral with the formula PbMoO4. It can be most often found as thin tabular crystals with a bright orange-red to yellow-orange color, sometimes brown, although the color can be highly variable. In its yellow form it is sometimes called "yellow lead ore".
Coffinite is a uranium-bearing silicate mineral with formula: U(SiO4)1−x(OH)4x.
Vivianite (Fe2+
Fe2+
2(PO
4)
2·8H
2O) is a hydrated iron phosphate mineral found in a number of geological environments. Small amounts of manganese Mn2+, magnesium Mg2+, and calcium Ca2+ may substitute for iron Fe2+ in the structure. Pure vivianite is colorless, but the mineral oxidizes very easily, changing the color, and it is usually found as deep blue to deep bluish green prismatic to flattened crystals.
Vivianite crystals are often found inside fossil shells, such as those of bivalves and gastropods, or attached to fossil bone.
Jadeite is a pyroxene mineral with composition NaAlSi2O6. It is hard (Mohs hardness of about 6.5 to 7.0), very tough, and dense, with a specific gravity of about 3.4. It is found in a wide range of colors, but is most often found in shades of green or white. Jadeite is formed only in subduction zones on continental margins, where rock undergoes metamorphism at high pressure but relatively low temperature.
Dickite is a phyllosilicate clay mineral named after the metallurgical chemist Allan Brugh Dick, who first described it. It is chemically composed of 20.90% aluminium, 21.76% silicon, 1.56% hydrogen and 55.78% oxygen. It has the same composition as kaolinite, nacrite, and halloysite, but with a different crystal structure (polymorph). Dickite sometimes contains impurities such as titanium, iron, magnesium, calcium, sodium and potassium.
Todorokite is a rare complex hydrous manganese oxide mineral with the chemical formula (Na,Ca,K,Ba,Sr)
1-x(Mn,Mg,Al)
6O
12·3-4H
2O. It was named in 1934 for the type locality, the Todoroki mine, Hokkaido, Japan. It belongs to the prismatic class 2/m of the monoclinic crystal system, but the angle β between the a and c axes is close to 90°, making it seem orthorhombic. It is a brown to black mineral which occurs in massive or tuberose forms. It is quite soft with a Mohs hardness of 1.5, and a specific gravity of 3.49 - 3.82. It is a component of deep ocean basin manganese nodules.
Descloizite is a rare mineral species consisting of basic lead and zinc vanadate, (Pb, Zn)2(OH)VO4, crystallizing in the orthorhombic crystal system and isomorphous with olivenite. Appreciable gallium and germanium may also be incorporated into the crystal structure.
Various theories of ore genesis explain how the various types of mineral deposits form within Earth's crust. Ore-genesis theories vary depending on the mineral or commodity examined.
Schreyerite (V2Ti3O9), is a vanadium, titanium oxide mineral found in the Lasamba Hill, Kwale district in Coast Province, Kenya. It is polymorphous with kyzylkumite.
Goldmanite is a green or greenish-brown silicate mineral of the garnet group with a chemical formula of Ca3(V3+,Al,Fe3+)2(SiO4)3.
Mottramite is an orthorhombic anhydrous vanadate hydroxide mineral, PbCu(VO4)(OH), at the copper end of the descloizite subgroup. It was formerly called cuprodescloizite or psittacinite (this mineral characterized in 1868 by Frederick Augustus Genth). Duhamelite is a calcium- and bismuth-bearing variety of mottramite, typically with acicular habit.
Paramontroseite (V4+O2) is a relatively rare orthorhombic vanadium oxide mineral in the Ramsdellite group. Synthetic paramontroseite may have applications in medicine, batteries and electronics.
