HAKITE-(Hg)
HAKITE-(Hg) Hakite – (Cu,Hg)3(Sb,As)(Se,S)3 – is an extremely rare sulfosalt (selenide). It has no importance as an ore. It is classified in the Tetrahedrite Group, in the Hakite Subgroup, together with hakite-(Cd), hakite-(Fe) and hakite-(Zn). It contains 26.18% Cu, 16.53% Hg, 16.05% Sb, 3.70% As, 33.83% Se, and 3.70% S. 1. Characteristics Crystal system: Cubic […]
HEULANDITE
HEULANDITE Heulandite – (Ca,Na,K)5(Si27Al9)O72.26H2O – is a tectosilicate of the Zeolite Group. It is a very common mineral, abundant in certain situations. It has great importance as an ore when it occurs cryptocrystalline. When it occurs hydrothermal, in larger crystals, it has only some importance as a collection mineral. “Heulandite” is actually not a mineral, […]
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 […]