Hornblende is a complex inosilicate series of minerals. It is not a recognized mineral in its own right, but the name is used as a general or field term, to refer to a dark amphibole. Hornblende minerals are common in igneous and metamorphic rocks.
Hapkeite is a mineral discovered in the Dhofar 280 meteorite found in 2000 in Oman on the Arabian peninsula. The meteorite is believed to originate from the Moon; specifically, it appears to be a fragment of lunar highland breccia. Hapkeite's composition is of silicon and iron, and it is similar to other silicon-iron minerals found on Earth. An impact on the Moon is thought to have launched the partially molten or vaporized material into orbit.
Forsterite (Mg2SiO4; commonly abbreviated as Fo; also known as white olivine) is the magnesium-rich end-member of the olivine solid solution series. It is isomorphous with the iron-rich end-member, fayalite. Forsterite crystallizes in the orthorhombic system (space group Pbnm) with cell parameters a 4.75 Å (0.475 nm), b 10.20 Å (1.020 nm) and c 5.98 Å (0.598 nm).
Enstatite is a mineral; the magnesium endmember of the pyroxene silicate mineral series enstatite (MgSiO3) – ferrosilite (FeSiO3). The magnesium rich members of the solid solution series are common rock-forming minerals found in igneous and metamorphic rocks. The intermediate composition, (Mg,Fe)SiO
3, has historically been known as hypersthene, although this name has been formally abandoned and replaced by orthopyroxene. When determined petrographically or chemically the composition is given as relative proportions of enstatite (En) and ferrosilite (Fs) (e.g., En80Fs20).
Aenigmatite, also known as Cossyrite after Cossyra, the ancient name of Pantelleria, is a sodium, iron, titanium inosilicate mineral. The chemical formula is Na2Fe2+5TiSi6O20 and its structure consists of single tetrahedral chains with a repeat unit of four and complex side branches. It forms brown to black triclinic lamellar crystals. It has Mohs hardness of 5.5 to 6 and specific gravity of 3.74 to 3.85. Aenigmatite forms a solid-solution series with wilkinsonite, Na2Fe2+4Fe3+2Si6O20.
Babingtonite is a calcium iron manganese inosilicate mineral with the formula Ca2(Fe,Mn)FeSi5O14(OH). It is unusual in that iron(III) completely replaces the aluminium so typical of silicate minerals. It is a very dark green to black translucent mineral crystallizing in the triclinic system with typically radial short prismatic clusters and druzy coatings. It occurs with zeolite minerals in cavities in volcanic rocks. Babingtonite contains both iron(II) and iron(III) and shows weak magnetism. It has a Mohs hardness of 5.5 to 6 and a specific gravity of 3.3.
Pyroxferroite (Fe2+,Ca)SiO3 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 during the 1969 Apollo 11 mission. 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 at high pressures and temperatures. The mineral is metastable and gradually decomposes at ambient conditions, but this process can take billions of years.
Pigeonite is a mineral in the clinopyroxene subgroup of the pyroxene group. It has a general formula of (Ca,Mg,Fe)(Mg,Fe)Si2O6. The calcium cation fraction can vary from 5% to 25%, with iron and magnesium making up the rest of the cations.
Haxonite is an iron nickel carbide mineral found in iron meteorites and carbonaceous chondrites. It has a chemical formula of (Fe,Ni)23C6, crystallises in the cubic crystal system and has a Mohs hardness of 5+1⁄2 - 6.
Akimotoite is a rare silicate mineral in the ilmenite group of minerals, with the chemical formula (Mg,Fe)SiO3. 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 R3. It is the silicon analogue of geikielite (MgTiO3).
Brownleeite is a silicide mineral with chemical formula MnSi. It was discovered by researchers of the Johnson Space Center in Houston while analyzing the Pi Puppid particle shower of the comet 26P/Grigg-Skjellerup. The only other known natural manganese silicide is mavlyanovite, Mn5Si3.
Awaruite is a naturally occurring alloy of nickel and iron with a composition from Ni2Fe to Ni3Fe.
Roaldite is a rare meteorite mineral containing iron, nickel and nitrogen. Its chemical formula is (Fe,Ni)4N.
Suessite is a rare iron silicide mineral with chemical formula: Fe3Si. The mineral was named after Professor Hans E. Suess. It was discovered in 1982 during the chemical analysis of The North Haig olivine pigeonite achondrite (ureilite). It is a cream white color in reflected light, and ranges in size from 1 μm "blebs" to elongated grains that can reach up to 0.45 cm in length. This mineral belongs in the isometric crystal class. The isometric class has crystallographic axes that are all the same length and each of the three axes perpendicular to the other two. It is isotropic, has a structural type of DO3 and a crystal lattice of BiF3.
Daubréelite is a rare sulfide mineral. It crystallizes with cubic symmetry and has chemical composition of Fe2+Cr3+2S4. It usually occurs as black platy aggregates.
Djerfisherite is an alkali copper–iron sulfide mineral and a member of the djerfisherite group.
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.
Linzhiite is an iron silicide mineral with the formula FeSi2. It was discovered in the 1960s in Donetsk Oblast in Soviet Union, and named ferdisilicite, but was not approved by the International Mineralogical Association. It was later rediscovered near Linzhi in Tibet. Linzhiite occurs together with other rare iron silicide minerals, xifengite (Fe5Si3) and naquite (FeSi).
Naquite is an iron silicide mineral with the formula FeSi. It was discovered in the 1960s in Donetsk Oblast in Soviet Union, and named fersilicite, but was not approved by the International Mineralogical Association. It was later rediscovered in Nagqu, Tibet. Naquite occurs together with other rare iron silicide minerals, xifengite (Fe5Si3) and linzhiite (FeSi2).
Phosphide silicides or silicide phosphides or silicophosphides are compounds containing anions composed of silicide (Si4−) and phosphide (P3−). They can be considered as mixed anion compounds. They are distinct from the phosphidosilicates, which have the phosphorus bonded to the silicon. Related compounds include the phosphide carbides, germanide phosphides, nitride silicides, and antimonide silicides.
