HAUSMANNITE
HAUSMANNITE Hausmannite – Mn3O4 – is a relatively rare oxide that can occur in a variety of geological situations. Generally hausmannite is an ore of Mn of secondary importance; only in some deposits it has economic importance. It forms crystals up to 7.5 cm. 1. Characteristics Crystal system: Tetragonal, bipiramidal ditetragonal. Color: Black-brown to grayish. […]
HIPERSTHENE
HIPERSTHENE See “Enstatite” “Hipersthene” was discredited as species name by the CNMMN Pyroxene Subcommittee in 1988.
HORNBLENDE GREEN
GREEN HORNBLENDE “Green Hornblende” is not a mineral, but just a term referring to very common rock-forming silicates of the Amphibole Supergroup – (Na,K)0-1Ca2(Mg,Fe,Al)5(Si,Al)8O22(OH)2. Hornblendes are not an ore. Thus, “green hornblende” is a generic term used for dark green to black amphiboles of complex chemical compositions, which form 3 series: the Barroisite Series, the […]
HÜBNERITE
HÜBNERITE See “Wolframite”
HEMATITE
HEMATITE Hematite – Fe2O3 – is a very common oxide. It is the main iron ore, as it contains approximately 70% iron. Hematite is one of several iron oxides and forms a complete solution (isomorphism) with ilmenite (FeTiO3) at temperatures above 950°C. At low temperatures there is still a very low degree of mixing with […]
HALITE
HALITE Halite – HCl – is a halide with a restricted but worldwide distribution. It has been extremely important since the Neolithic as a salt ore and later as a base for obtaining chlorine. When combined with K and Mg salts, it also forms an ore of these elements. May contain I, Br, Fe and […]