Geographic Minerals

Omphacite is a silicate mineral in the clinopyroxene group with the formula: (Ca, Na)(Mg, Fe2+, Al)Si2O6 is a rare pyroxene group member. It is a…

Oldhamite is a calcium magnesium sulfide mineral with the chemical formula (Ca,Mg)S. It is a mineral CaS that is found in meteorites and is composed…

Olivenite is a copper arsenate mineral with the chemical formula Cu2AsO4OH. It is a mineral that is olive green, dull brown, or yellowish in color…

Okenite (CaSi2O5·2H2O) is a silicate mineral commonly found with zeolites. It is most commonly found within basalt geodes as small white “cotton ball” formations. It…

Olgite is a rare blue-green colored phosphate mineral series that forms microscopic prismatic crystals that are trigonal in structure. It is a trigonal-hexagonal scalenohedral mineral…

Niobite, also known as Columbite, [(Fe, Mn)Nb2O6], is a niobium ore that is black in color. It is a black mineral composed of niobium oxide…

Coltan is a dull black metallic ore that contains the elements niobium and tantalum. It is a dull black ore composed of columbite and tantalite…

Nephrite is a calcium, magnesium, and iron-rich amphibole mineral similar to tremolite or actinolite (aggregates of which also make up one form of asbestos). It…

Nyerereite is a mineral with the formula Na2Ca(CO3)2 that is extremely rare. It is a chemical composition in which the alkali element is clearly present,…

Nuragheite is a rare natural thorium molybdate discovered in Su Seinargiu, Sarroch, Cagliari, Sardegna, Italy, with the formula Th(MoO4)2•H2O. The name is derived from the…

Troilite is a pyrrhotite mineral, which means it’s a rare iron sulfide mineral. Although it may be found on Earth, meteorites have a higher concentration…

Siderolites, or stony-iron meteorites, are meteorites that contain significant concentrations of both rocky materials (silicates) and nickel-iron metal. Meteorites are classified into three primary groups:…