Oxide minerals

Akaogiite (IMA symbol Aka) is an exceedingly rare mineral, one of the natural forms of titanium dioxide (TiO2). It is a high-pressure polymorph of TiO2, along with anatase, brookite and another high-pressure phase called "TiO2 II". Rutile is the stable polymorph of TiO2, most commonly found at standard temperatures and pressures.

Wodginite is a manganese, tin, tantalum oxide mineral with the chemical formula . It may also include significant amounts of niobium.

Marthozite is an orthorhombic mineral that has a general formula of Cu(UO2)3(SeO3)3(OH)2·7H2O. It was named after Belgian mineralogist Aimé Marthoz (1894–1962), former Director-general of the Union Minière du Haut Katanga (UMHK).

Seeligerite is a rare complex lead chloride iodate mineral with formula: Pb3Cl3(IO3)O. It is a yellow mineral crystallizing in the orthorhombic system. It has perfect to good cleavage in two directions and a quite high specific gravity of 6.83 due to the lead content. It is translucent to transparent with refractive indices of nα=2.120 nβ=2.320 nγ=2.320.

thumb | right | White vitreous crystal aggregates of the extremely rare Al mineral akdalaite from the TL (Solnechnoye Mine, Kara-Oba, Karazhal, Ulytau Region, Kazakhstan) and only one of 6 known localities worldwide. Ex Vandenbroucke Museum collection from Waregem, Belgium. Akdalaite (IMA symbol: Akd) is a very rare mineral found in Kazakhstan and has the formula . It was formerly believed to be . It is therefore the same as tohdite an artificially produced phase. Studies on the crystal structure and spectra indicate that this is an aluminium oxide hydroxide.

Tantite is a rare tantalum oxide mineral with formula: Ta2O5. Tantite forms transparent microscopic colorless triclinic - pedial crystals with an adamantine luster. It has a Mohs hardness of 7 and a high specific gravity of 8.45. Chemical analyses show minor inclusion (1.3%) of niobium oxide.

Geikielite is a magnesium titanium oxide mineral with formula: MgTiO3. It is a member of the ilmenite group. It crystallizes in the trigonal system forming typically opaque, black to reddish black crystals.

Zincochromite is a zinc chromium oxide mineral with the formula ZnCr2O4. It is the zinc analogue of chromite, hence the name. It was first described in 1987 as an occurrence in a uranium deposit near Lake Onega, Russia. It has also been reported from Dolo Hill, New South Wales, Australia, and from the Tarkwa Mine in the Ashanti gold belt of Ghana.

Nickel–Strunz 9 ed mineral class number 4

Bartelkeite is an exceptionally rare mineral, one of scarce natural germanium compounds. The formula was originally assumed to be PbFeGe3O8, bartelkeite was later shown to be isostructural with a high-pressure form of the mineral lawsonite. Thus, its correct formula is PbFeGe(Ge2O7)(OH)2•H2O. Bartelkeite and mathewrogersite are minerals with essential (dominant) lead, iron and germanium. Both come from Tsumeb, Namibia - a world's "capital" of germanium minerals.

Tugarinovite is a rare molybdenum oxide mineral with formula MoO2. It occurs as a primary mineral phase associated with metasomatism in a sulfur deficient reducing environment. In the type locality it occurs with uraninite, molybdenite, galena, zircon and wulfenite.

Tapiolite [(Fe, Mn)(Nb, Ta)2O6] is a black mineral series that is an ore of niobium and tantalum. The tapiolite group includes tapiolite-(Fe) or ferrotapiolite and tapiolite-(Mn) or manganotapiolite. Tapiolite-(Fe) is by far the more common of the two.

Heterogenite is a natural tri-valent cobalt oxyhydroxide mineral. It is the most abundant oxidised cobalt mineral in the Katanga Copperbelt, a region in the Democratic Republic of the Congo. About 70% of known heterogenite is located in the DRC.

Davidite is a rare earth oxide mineral with chemical end members Lanthanum (La) and Cerium (Ce). It exists in two forms: Davidite-(La) discovered at Radium Hill mine, South Australia in 1906 and named by Douglas Mawson for Australian geologist Tannatt William Edgeworth David (1858-1934). Davidite-(Ce) first described in 1960 from Vemork, Iveland, Norway.

Schwertmannite is an iron-oxyhydroxysulfate mineral with an ideal chemical formula of or . It is an opaque tetragonal mineral typically occurring as brownish yellow encrustations. It has a Mohs hardness of 2.5 – 3.5 and a specific gravity of 3.77 – 3.99.

Nsutite is a manganese oxide mineral with formula: (Mn4+1−xMn2+xO2-2x(OH)2x where x = 0.06–0.07). It is found in most large manganese deposits and was first discovered in Nsuta, Ghana. Since then, it has been found worldwide. Nsutite is a dull mineral with a hardness of 6.5–8.5 and an average specific gravity of 4.45. Nsutite has been used as a cathode in zinc–carbon batteries, but synthetic manganese oxide is gradually replacing it.

Biehlite is an exceptionally rare mineral, an antimony arsenic bearing molybdate with formula . It comes from Tsumeb.

Ramsdellite (Mn4+O2) is an orthorhombic manganese dioxide mineral. It is relatively uncommon, and is usually found in deposits containing other manganese oxide crystals.

Grossite is a calcium aluminium oxide mineral with formula CaAl4O7. It is a colorless to white vitreous mineral which crystallizes in the monoclinic crystal system.

Ixiolite is an accessory oxide mineral found in granitic pegmatites. It is an oxide with the general chemical formula or .

Cleusonite is a member of the crichtonite group of minerals with the chemical formula . This group of minerals contains approximately thirteen complex metal titanates. The structures of minerals of this group is complicated by frequent fine-scale twinning and metamictization due to radioactive elements. The crichtonite group consists of members of related mineral species of the type A{BC2D6E12}O38 which are characterized by their predominant cations (as seen in crichtonite (Sr), senaite (Pb), davidite (REE + U), landauite (Na), loveringite (Ca), lindsleyite (Ba), and mathiasite (K).

blue gemstone

Murdochite is a mineral combining lead and copper oxides with the chemical formula  (x ≤ 0.5).

Haggertyite is a rare barium, iron, magnesium, titanate mineral: Ba(Fe2+6Ti5Mg)O19 first described in 1996 from the Crater of Diamonds State Park near Murfreesboro in Pike County, Arkansas. The microscopic metallic mineral crystallizes in the hexagonal system and forms tiny hexagonal plates associated with richterite and serpentinitized olivine of mafic xenoliths in the lamproite host rock. It is an iron(II) rich member of the magnetoplumbite group. It is a light grey opaque mineral with calculated Mohs hardness of 5.

Akimotoite is a rare silicate mineral in the ilmenite group of minerals, with the chemical formula . It is polymorphous with pyroxene and with bridgmanite, a natural silicate perovskite that is the most abundant mineral in Earth's silicate mantle. Akimotoite has a vitreous luster, is colorless, and has a white or colorless streak. It crystallizes in the trigonal crystal system in space group R. It is the silicon analogue of geikielite (MgTiO3).

Kadyrelite is a mineral with the chemical formula discovered in 1987.

Akhtenskite is a manganese oxide mineral with the chemical formula of MnO2 (or: ε-Mn4+O2) that was named after the Akhtensk deposit in Russia, where it was first discovered and noted in 1979. It can be found in the Akhtensk brown ironstone deposit, in the southern Ural Mountains, on Mt. Zarod, on the Sikhote-Alin Mountains, and in the Primorskiy Krai, all in Russia.

Wattersite is a rare mercury chromate mineral with the formula Hg+14Hg+2Cr+6O6. It occurs in association with native mercury and cinnabar in a hydrothermally altered serpentinite. It was first described from Clear Creek claim, San Benito County, California, USA in 1961. It was named to honor Californian mineral collector Lucius "Lu" Watters.

Zimbabweite is a yellow brown mineral with orthorhombic crystal habit and a hardness of 5, with formula . It is generally classed as an arsenite but is notable for also containing niobium and tantalum. It was discovered in 1986 in kaolinized pegmatite, i.e. weathered to clay, in Zimbabwe.

Sillénite or sillenite is a mineral with the chemical formula Bi12SiO20. It is named after the Swedish chemist Lars Gunnar Sillén, who mostly studied bismuth-oxygen compounds. It is found in Australia, Europe, China, Japan, Mexico and Mozambique, typically in association with bismutite.

Azoproite is a rare manganese iron borate mineral with the chemical formula (Mg,Fe)(Fe,Ti,Mg)(BO)O. It was first identified near Lake Baikal, Russia. It was named after the Association pour l'Etude Géologique des Zones Profondes de l'Ecorce Terrestre, whose acronym is AZOPRO in French.

Rynersonite is an oxide mineral. It crystallizes in the orthorhombic crystal system. It is dull, translucent mineral, fibrous in nature. Usually off-white to pale pink in color. It occurs in granitic pegmatites and was first described for an occurrence in San Diego County, California in 1978.

Krotite is a natural mineral composed of calcium, aluminium and oxygen, with the molecular formula CaAl2O4. It is the low-pressure dimorph of CaAl2O4, of which the high-pressure dimorph is named dmitryivanovite.

Changbaiite (PbNb2O6) is a member of the oxide mineral class in which the mineral contains oxygen which is grouped along with one or two metal ion. Changbaiite is classified as a multiple Oxide XY2O6 and it generally has an ionic bond. Furthermore, it is also orthorhombic at a temperature of 25 °C and it changes to orthorhombic-tetragonal at 570 °C.

Aeschynite-(Nd) is a rare earth mineral of neodymium, cerium, calcium, thorium, titanium, niobium, oxygen, and hydrogen with the chemical formula . Its name comes from the Greek word for "shame". Its Mohs scale rating is 5 to 6. It is a member of the hydroxide minerals.

thumb | right | Rock containing lyonsite Lyonsite (Cu3Fe+34(VO4)6) is a rare black vanadate mineral that is opaque with a metallic lustre. It crystallizes in the orthorhombic crystal system. Lyonsite often occurs as small tabular typically well formed crystals. Lyonsite has a good cleavage and a dark gray streak.

Titanowodginite is a mineral with the chemical formula MnTiTa2O8. Titanowodginite has a Mohs hardness of 5.5 and a vitreous luster. It is an iridescent dark brown to black crystal that commonly forms in a matrix of smoky quartz or white beryl in a complex zoned pegmatite.

Amakinite (IMA symbol: Amk) is a semi transparent yellow-green hydroxide mineral belonging to the brucite group that was discovered in 1962. Its chemical formula is written as (Fe2+,Mg)(OH)2. It usually occurs in the form of splotchy, anhedral crystals forming within a group or structure in other minerals or rocks, such as kimberlite (occurring in diamond-rich eruptive pipe). Its composition is as follows:

Scrutinyite is a rare oxide mineral and is the alpha crystalline form of lead dioxide (α-PbO2), plattnerite being the other, beta form. The mineral was first reported in 1988 and its name reflects the scrutiny and efforts required to identify it from a very limited amount of available sample material.

Cerianite-(Ce) is a relatively rare oxide mineral, belonging to uraninite group with the formula . It is one of a few currently known minerals containing essential tetravalent cerium, the other examples being stetindite and dyrnaesite-(La).

Loveringite is a rare metallic oxide mineral of the crichtonite group with the chemical formula . It is a late-stage magmatic mineral, formed in the residual melt of mafic layered intrusions in either the olivine-chromite, pyroxene, or plagioclase-rich layers.

Xieite is an iron chromium oxide mineral with formula Fe2+Cr2O4. It is a member of the spinel group and a high pressure polymorph of chromite.

Gauthierite is a very rare mineral with the idealised chemical sum formula . It is a radioactive, hydrated orange-coloured lead potassium uranyl oxide hydroxide. It was found by analysing old mineral specimens, and is only known from one locality, the Shinkolobwe Mine in the Democratic Republic of the Congo. The mineral was named in honour of Gilbert Gauthier, a Belgian collector of uranium minerals, who provided a sample to one of the co-authors of the study that first identified it in 2017.

oxide mineral

thumb | right Daubréeite is a rare bismuth oxohalide mineral with formula . It is a creamy-white to yellow-brown, soft, earthy clay–like mineral which crystallizes in the tetragonal crystal system. It is a member of the matlockite group.

Filipstadite is a very rare mineral of the spinel group, with the formula . It is isometric, although it was previously thought to be orthorhombic. When compared to a typical spinel, both the octahedral and tetrahedral sites are split due to cation ordering. Filipstadite is chemically close to melanostibite. The mineral comes from Långban, Sweden, a manganese skarn deposit famous for many rare minerals.

Janggunite is a rare manganese oxide mineral with the chemical formula .

Kamiokite is an iron-molybdenum oxide mineral with the chemical formula Fe2Mo3O8. The name kamiokite is derived from the locality, the Kamioka mine in Gifu Prefecture, Japan, where this mineral was first discovered in 1975.

Anthoinite (IMA symbol: Atn) is an aluminium tungsten oxide mineral with the chemical formula AlWO(OH). Its type locality is Maniema in the Democratic Republic of the Congo.

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.

Schreyerite (V2Ti3O9), is a vanadium, titanium oxide mineral found in the Lasamba Hill, Kwale district in Coast Province, Kenya. It is polymorphous with kyzylkumite.

Cesbronite is a copper-meteatellurate oxysalt mineral with the chemical formula Cu3Te6+O4(OH)4 (IMA 17-C). It is colored green and its crystals are orthorhombic dipyramidal. Cesbronite is rated 3 on the Mohs Scale. It is named after Fabien Cesbron (born 1938), a French mineralogist.

Allendeite, Sc4Zr3O12, is an oxide mineral. Allendeite was discovered in a small ultrarefractory inclusion within the Allende meteorite. This inclusion has been named ACM-1. It is one of several scandium rich minerals that have been found in meteorites. Allendeite is trigonal, with a calculated density of 4.84 g/cm3. The new mineral was found along with hexamolybdenum. These minerals, are believed to demonstrate conditions during the early stages of the Solar System, as is the case with many CV3 carbonaceous chondrites such as the Allende meteorite. It is named after the Allende meteorite

Hydrokenoelsmoreite is a hydrous tungsten oxide mineral with formula □2W2O6(H2O). Hydrokenoelsmoreite is a colorless to white, translucent isometric mineral. It has a Mohs hardness of 3, exhibits no cleavage and has a splintery fracture. It has a vitreous to adamantine luster. It is optically isotropic with an index of refraction of n = 2.24.

Walfordite is a very rare tellurite mineral that was discovered in Chile in 1999. The mineral is described as orange with orange-yellow streak, and is determined to have a chemical formula of Fe3+,Te6+Te4+3O8 with minor titanium and magnesium substitution resulting in an approximate empirical formula of (Fe3+,Te6+,Ti4+,Mg)(Te4+)3O8.

Hiärneite is an oxide mineral named after the Swedish geologist Urban Hiärne (1641–1727). The mineral can be found in rocks that mainly consists of fine grained phlogopite. Hiärneite is the first known mineral that contains both of the chemical elements antimony and zirconium. The mineral was described in 1997 for its occurrence in a skarn environment in Långban iron–manganese deposit of the Filipstad district, Värmland, Sweden.

thumb | 220x124px | right | alt= SEM BSE images showing kaitianite (Ktn) with tistarite (Tta), Ti,Al,Zr-oxide (TAZ), MgTi3+2Al4SiO12 phase (MTAS), spinel (Spl), sapphirine (Spr), and Ti-sulfide (Ti-S) in corundum Grain 1125C2. The upper rectangular area in (b) are enlarged in (c) | SEM BSE images showing kaitianite (Ktn) with tistarite (Tta), Ti,Al,Zr-oxide (TAZ), MgTi3+2Al4SiO12 phase (MTAS), spinel (Spl), sapphirine (Spr), and Ti-sulfide (Ti-S) in corundum Grain 1125C2. The upper rectangular area in (b) are enlarged in (c) Tistarite is an exceedingly rare mineral with the formula Ti2O3, thus

Ordoñezite or ordóñezite is a rare tetragonal zinc antimonate mineral with chemical formula: ZnSb2O6.

Rakovanite, (NH4)3Na3(V10O28) · 12H2O; formerly given as Na3(H3V10O28).15H2O; later, the ammonium ion was shown to be present and essential, is a member of the pascoite family. It is a transparent, brittle mineral occurring in the monoclinic crystal system. It is orange in color and has an orange-yellow colored streak. Rakovanite is soft with a Mohs hardness of 1 and a calculated density of 2.407g cm−3. It does not fluoresce in long- or short-wave ultraviolet radiation. Rakovanite crystals are up to one mm in maximum dimension and vary in habit from blocky to prismatic on [001], commonly exhib

Spriggite is an uranyl hydroxide mineral with chemical formula Pb3(UO2)6O8(OH)2·3H2O. Its type locality is Mt Painter region, Arkaroola region, Flinders Ranges, South Australia. It was named after Reginald C. Sprigg (1919–1994).