Stannite
Stannite | |
---|---|
Stannite from the Fabulosa Mine, Larecaja Province, La Paz Department, Bolivia (crystal size 2 mm) | |
General and classification | |
chemical formula | Cu 2 FeSnS 4 |
Mineral class (and possibly department) |
Sulfides and sulfosalts |
System no. to Strunz and to Dana |
2.CB.15a ( 8th edition : II / C.06) 02.09.02.01 |
Crystallographic Data | |
Crystal system | tetragonal |
Crystal class ; symbol | tetragonal-scalenohedral 4 2 m |
Space group | I 4 2 m |
Lattice parameters | a = 5.443 Å ; c = 10.73 Å Please complete the source as an individual reference |
Formula units | Z = 2 Please complete the source as an individual reference |
Twinning | after (111) |
Physical Properties | |
Mohs hardness | 4th |
Density (g / cm 3 ) | 4.3 to 4.5 |
Cleavage | indistinct |
Break ; Tenacity | uneven, brittle |
colour | steel gray with olive green tint |
Line color | black |
transparency | opaque |
shine | Metallic luster |
Other properties | |
Chemical behavior | decomposes into ENT 3 |
Stannite , also known in mining as tin grit or tin-copper luster or synonymously as stannin , cassiterolamprite or volfsonite , is a mineral from the mineral class of sulfides and sulfosalts with the chemical formula Cu 2 FeSnS 4 . Stannite crystallizes in the tetragonal crystal system , but mostly occurs in coarse, granular masses of steel-gray color and only very rarely forms crystals in the shape of a tetrahedron. Some stannites can contain up to 2% indium through substitution .
Stannite is not one of the stannite salts of stannic acid .
Etymology and history
The mineral name is derived from the chemical element tin ( Latin stannum ), which is contained in stannite. The mining of stannite is for the 3rd millennium BC. In Tajikistan . Stannite was first chemically investigated in 1797 and 1810 by Martin Heinrich Klaproth . He examined ore from St Agnes in Cornwall , which is also considered a type locality .
classification
In the Strunz system , stannite is classified as sulfides and sulfosalts. It is counted among the sulphides with a ratio of metal to sulfur, selenium or tellurium of 1: 1. In the eighth edition , it formed a group with barquitasite , briartite , černýite , famatinite , ferrokësterite , hocartite , kësterite , kuramite , luzonite , permingeatite , petrukite , pirquitasite , rhodostannite , sakuraiite , toyohaite and velikite . In the ninth edition , the sulfides are also subdivided according to cations, where stannite mt černýite, ferrokësterite, hocartite, idaite, kësterite, kuramite, mohite, pirquitasite, stannoidite and velikite form a subgroup of metal sulfides with a ratio of metal to sulfur, selenium or tellurium of 1: 1 and zinc , iron , copper or silver .
In the systematics of minerals according to Dana it forms with černýite, briartite, kuramite, sakuraiite, hocartite, pirquitasite, velikite, kësterite, ferrokësterite and barquillite the stannite subgroup of sulphides - including selenides and tellurides - with the composition Am Bn Xp, with ( m + n): p = 1: 1.
Modifications and varieties
Stannite and kesterite form a mixed crystal row in which iron and zinc can be exchanged for one another. In stannite, iron predominates, while kësterite contains more zinc. In addition, a rare zinc-containing variety is known.
Education and Locations
Stannite is a typical mineral of tin-bearing hydrothermal veins , where it occurs mostly inferior to cassiterite . Other common accompanying minerals are sphalerite , galena , arsenopyrite , chalcopyrite and pyrite .
A large number of stannite sites are known. In addition to the type locality, Cínovec in the Czech Republic , Broken Hill and Zeehan in Australia , Oruro , Chocaya and Cerro Rico in Bolivia , Keystone in the United States , Fredericton in Canada and Yizhang in the People's Republic of China are among the important stannite deposits.
Crystal structure
Stannite crystallizes in the tetragonal crystal system in the space group I 4 2 m with the lattice parameters a = 5.443 Å and c = 10.73 Å as well as two formula units per unit cell .
use
As an ore in its own right , stannite is rather insignificant, but is also extracted when quarrying cassiterite deposits . Stannite can be of local importance for Cu production.
See also
Web links
literature
- P. Ramdohr, H. Strunz: Klockmanns textbook of mineralogy. 16th edition. Enke Verlag, Stuttgart 1987, ISBN 3-432-82986-8 .
- G. Strübel, SH Zimmer: Lexicon of Minerals . Enke Verlag, Stuttgart 1991, ISBN 3-432-92722-3 .
- Museum Bochum: miners among hunters and collectors. In: Aid. Issue 4-1999, p. 60.
- Stannite. In: Anthony et al.: Handbook of Mineralogy. 1, 1990, p. 101 (pdf) .
Individual evidence
- ↑ Webmineral - Stannite (English)
- ↑ Martin Heinrich Klaproth: Chemical investigation of the tin gravel. In: Contributions to the chemical knowledge of mineral bodies. Volume 5, 1810, pp. 228-230, doi: 10.3931 / e-rara-20566 (free full text).
- ^ List of minerals according to Dana at webmineral.com
- ↑ Kësterite-Stannite Series at mindat.org (Eng.)
- ↑ Zincian Stannite at mindat.org (Eng.)