HEDENBERGITE
HEDENBERGITE Hedenbergite – CaFe2+Si2O6 – is an inosilicate, a rarer monoclinic pyroxene (clinopyroxene), characteristic of very specific paragenesis. It has no economic importance. It is part of the diopside – augite – hedenbergite solid solution series and may contain, as impurities, Ti, Mg, Mn, Na, K, Al and Zn. It forms epitaxy with babingtonite and […]
HORNBLENDE BROWN
BROWN HORNBLENDE Brown hornblende – Na(2)Ca(2)(Mg,Fe2+)4(Fe3+,Ti,Al)(OH)2|AlSi7O22 – is an inosilicate of the Amphibole Supergroup. It is a rarer mineral, characteristic of some types of igneous rocks. It has no economic importance. “Brown Hornblende” is actually not a mineral, but just an informal name, a nickname, for brown to black amphiboles of complex compositions such as […]
HAÜYNE
HAÜYNE Haüyne – (Na,Ca)4-8(Al6Si6(O,S)24)(SO4,Cl)1-2 – is a tectosilicate, a relatively rare feldspathoid, characteristic of silica-subsaturated sodic volcanic rocks. It is sought after as a collector mineral and can be used as a gemstone. Haüyne is part of the Sodalite Group, along with lazurite, nosean, sodalite, tsaregorodtsevite and vladimirivanovite. It may contain some K. There is […]
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. […]
HYPERSTHENE
HYPERSTHENE See “Enstatite” “Hypersthene” 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 […]