Germanite | |
---|---|
General | |
Category | Sulfide mineral |
Formula (repeating unit) | Cu26Ge4Fe4S32 [1] |
IMA symbol | Ger [2] |
Strunz classification | 2.CB.30 |
Dana classification | 2.9.4.2 |
Crystal system | Isometric |
Crystal class | Hextetrahedral (43m) H-M symbol: (4 3m) |
Space group | P43n |
Identification | |
Color | Reddish grey tarnishing to dark brown |
Crystal habit | Usually massive; rarely as minute cubic crystals |
Cleavage | None |
Tenacity | Brittle |
Mohs scale hardness | 4 |
Luster | Metallic |
Streak | Dark grey to black |
Diaphaneity | Opaque |
Specific gravity | 4.4 to 4.6 |
Other characteristics | Cell data: a = 10.585 Å Z = 1 [3] |
References | [4] [5] |
Germanite is a rare copper iron germanium sulfide mineral, Cu26Fe4Ge4S32. It was first discovered in 1922, and named for its germanium content. [3] It is only a minor source of this important semiconductor element, which is mainly derived from the processing of the zinc sulfide mineral sphalerite. [6] Germanite contains gallium, zinc, molybdenum, arsenic, and vanadium as impurities. [3]
Its type locality is the Tsumeb Mine in Namibia where it occurs in a hydrothermal polymetallic ore deposit in dolomite in association with renierite, pyrite, tennantite, enargite, galena, sphalerite, digenite, bornite and chalcopyrite. [5] It has also been reported from Argentina, Armenia, Bulgaria, Cuba, Democratic Republic of Congo (Zaire), Finland, France, Greece, Japan, Republic of Congo (Brazzaville), Russia and the United States. [3]
X-Ray Powder Diffraction [7] | ||||||||
---|---|---|---|---|---|---|---|---|
d spacing | 3.05 | 2.65 | 1.87 | 1.60 | 1.32 | 1.21 | 1.08 | 1.02 |
relative intensity | 10 | 1 | 7 | 4 | 1 | 2 | 2 | 1 |
Sphalerite is a sulfide mineral with the chemical formula (Zn, Fe)S. It is the most important ore of zinc. Sphalerite is found in a variety of deposit types, but it is primarily in sedimentary exhalative, Mississippi-Valley type, and volcanogenic massive sulfide deposits. It is found in association with galena, chalcopyrite, pyrite, calcite, dolomite, quartz, rhodochrosite, and fluorite.
Greenockite, also cadmium blende or cadmium ochre (obsolete) is a rare cadmium bearing metal sulfide mineral consisting of cadmium sulfide (CdS) in crystalline form. Greenockite crystallizes in the hexagonal system. It occurs as massive encrustations and as hemimorphic six-sided pyramidal crystals which vary in color from a honey yellow through shades of red to brown. The Mohs hardness is 3 to 3.5 and the specific gravity is 4.8 to 4.9.
Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver.
Acanthite is a form of silver sulfide with the chemical formula Ag2S. It crystallizes in the monoclinic system and is the stable form of silver sulfide below 173 °C (343 °F). Argentite is the stable form above that temperature. As argentite cools below that temperature its cubic form is distorted to the monoclinic form of acanthite. Below 173 °C acanthite forms directly. Acanthite is the only stable form in normal air temperature.
Chalcocite, copper(I) sulfide (Cu2S), is an important copper ore mineral. It is opaque and dark gray to black, with a metallic luster. It has a hardness of 2.5–3 on the Mohs scale. It is a sulfide with a monoclinic crystal system.
Pyrrhotite is an iron sulfide mineral with the formula Fe(1-x)S. It is a nonstoichiometric variant of FeS, the mineral known as troilite. Pyrrhotite is also called magnetic pyrite, because the color is similar to pyrite and it is weakly magnetic. The magnetism decreases as the iron content increases, and troilite is non-magnetic. Pyrrhotite is generally tabular and brassy/bronze in color with a metallic luster. The mineral occurs with mafic igneous rocks like norites, and may form from pyrite during metamorphic processes. Pyrrhotite is associated and mined with other sulfide minerals like pentlandite, pyrite, chalcopyrite, and magnetite, and has been found globally.
Wurtzite is a zinc and iron sulfide mineral with the chemical formula (Zn,Fe)S, a less frequently encountered structural polymorph form of sphalerite. The iron content is variable up to eight percent. It is trimorphous with matraite and sphalerite.
Cobaltite is an arsenide and sulfide mineral with the mineral formula CoAsS. It is the naming mineral of the cobaltite group of minerals, whose members structurally resemble pyrite (FeS2).
Hardystonite is a rare calcium zinc silicate mineral first described from the Franklin, New Jersey, U.S. zinc deposits. It often contains lead, which was detrimental to the zinc smelting process, so it was not a useful ore mineral. Like many of the famous Franklin minerals, hardystonite responds to short wave ultraviolet light, emitting a fluorescence from dark purple to bright violet blue. In daylight, it is white to gray to light pink in color, sometimes with a vitreous or greasy luster. It is very rarely found as well formed crystals, and these are usually rectangular in appearance and rock-locked.
Stannite is a mineral, a sulfide of copper, iron, and tin, in the category of thiostannates.
Gahnite, ZnAl2O4, is a rare mineral belonging to the spinel group. It forms octahedral crystals which may be green, blue, yellow, brown or grey. It often forms as an alteration product of sphalerite in altered massive sulphide deposits such as at Broken Hill, Australia. Other occurrences include Falun, Sweden where it is found in pegmatites and skarns; and, in the United States, Charlemont, Massachusetts; Spruce Pine, North Carolina; White Picacho district, Arizona; Topsham, Maine; and Franklin, New Jersey.
Boulangerite or antimonbleiblende is an uncommon monoclinic orthorhombic sulfosalt mineral, lead antimony sulfide, formula Pb5Sb4S11. It was named in 1837 in honor of French mining engineer Charles Boulanger (1810–1849), and had been a valid species since pre-IMA. It was first described prior to 1959, and is now grandfathered.
Franckeite, chemical formula Pb5Sn3Sb2S14, belongs to a family of complex sulfide minerals. Franckeite is a sulfosalt. It is closely related to cylindrite.
Argutite (GeO2) is a rare germanium oxide mineral. It is a member of the rutile group.
Gunningite is one of the minerals in the Kieserite group, with the chemical formula (Zn,Mn2+)SO4·H2O. Its name honours Henry Cecil Gunning (1901–1991) of the Geological Survey of Canada and a professor at the University of British Columbia.
Renierite is a rare copper zinc germanium bearing sulfide mineral with the chemical formula (Cu,Zn)11(Ge,As)2Fe4S16. It occurs at the Kipushi Mine, Democratic Republic of the Congo; and Namibia, among other places.
Kipushi is a town in Haut-Katanga province, Democratic Republic of the Congo. It lies 35 km southwest of the city of Lubumbashi, very close to the border with Zambia, at an altitude of 1329 m (4363 ft). The main economic activity of the town is mining. Kipushi is part of the Roman Catholic Diocese of Sakania–Kipushi.
Geerite is a copper sulfide mineral with the chemical formula Cu8S5. The mineral is named after the original collector, Adam Geer, of Utica, New York, US.
Semseyite is a rarely occurring sulfosalt mineral and is part of the class of lead antimony sulfides. It crystallizes in the monoclinic system with the chemical composition Pb9Sb8S21. The mineral forms dark gray to black aggregates.
Millerite or nickel blende is a nickel sulfide mineral, NiS. It is brassy in colour and has an acicular habit, often forming radiating masses and furry aggregates. It can be distinguished from pentlandite by crystal habit, its duller colour, and general lack of association with pyrite or pyrrhotite.