Geographic Minerals

Brownmillerite is a rare oxide mineral with chemical formula Ca2(Al, Fe)2O5. It is named for Lorrin Thomas Brownmiller (1902–1990), chief chemist of the Alpha Portland…

Brookite is the orthorhombic variant of titanium dioxide, TiO2, which occurs in four natural polymorphic forms (minerals with the same composition but different structure). It…

Bronzite is a member of the pyroxene group of minerals, belonging to enstatite and hypersthene to the orthorhombic series of the group. Rather than a…

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…

Bromellite, whose name derives from the Swedish chemist Magnus von Bromell (1670–1731), is a white oxide mineral, found in complex pegmatitic manganese-iron deposits, but is…

Bromyrite or bromargyrite is a natural mineral form of silver bromide found mainly in Mexico and Chile. Hardness is 1.5 to 2. Related are chlorargyrite…

Brochantite is a sulfate mineral, one of a number of cupric sulfates. Its chemical formula is Cu4SO4(OH)6. It is formed from the oxidation of copper…

Silicate perovskite (or bridgmanite) is (Mg, Fe)SiO3 and CaSiO3 (calcium silicate) when arranged in a perovskite structure. Silicate perovskites are mainly found in the lower…

Briartite is an opaque iron-grey metallic sulfide mineral, Cu2(Zn, Fe)GeS4 with traces of Ga and Sn, found inclusions in other germanium-gallium-bearing sulfides. It is a…

Brianyoungite is a secondary zinc carbonate mineral. It was named after Brian Young (born- 1947), a field geologist and mineralogist associated with the British Geological…

Brianite is a phosphate mineral with the chemical formula Na2CaMg(PO4)2. It is a phosphate mineral that was first identified in an iron meteorite. This mineral…

Brezinaite, discovered in 1969, is a rare mineral composed of chromium and sulfur. It was named in honor of Aristides Brezina (1848–1909), a past Director…