Stromeyerite
| Stromeyerite | |
|---|---|
 |
|
| General and classification | |
| other names |
|
| chemical formula | AgCuS |
|
Mineral class (and possibly department) |
Sulfides and sulfosalts |
|
System no. to Strunz and to Dana |
2.BA.40 ( 8th edition : II / B.06) 04/02/06/01 |
| Crystallographic Data | |
| Crystal system | orthorhombic |
| Crystal class ; symbol | orthorhombic-pyramidal; mm 2 |
| Space group | Cmc 2 1 (No. 36) |
| Lattice parameters | a = 4.06 Å ; b = 6.62 Å; c = 7.97 Å |
| Formula units | Z = 4 |
| Twinning | often on {001} |
| Physical Properties | |
| Mohs hardness | 2.5 to 3 |
| Density (g / cm 3 ) | 6.2 to 6.3 |
| Cleavage | is missing |
| colour | Gray |
| Line color | steel gray |
| transparency | opaque |
| shine | Metallic luster |
| Crystal optics | |
| Pleochroism | weak in air, strong in oil |
Stromeyerite (cypargyrite, copper silver luster) is a rarely occurring mineral from the mineral class of sulfides and sulfosalts . It crystallizes in the orthorhombic crystal system with the chemical formula AgCuS and mostly forms coarse, broken-in, massive aggregates of steel-gray color that turn blue. Prismatic crystals up to 5 mm in size are also rarely found . In addition to copper and silver , it can also contain traces of iron .
Etymology and history
The mineral was first discovered in 1832 by François Sulpice Beudant in the type locality Vrančice in Okres Příbram ( Czech Republic ). The first chemical investigation was carried out by the Göttingen chemistry professor Friedrich Stromeyer , after whom the mineral is also named.
classification
In the Strunz system , stromeyerite is classified as sulphides and sulphosalts. It is counted among the metal sulfides with a ratio of metal to sulfur of> 1: 1. In the 8th edition he formed a group with Brodtkorbit , Eukairit , Henryit , Imiterit , Jalpait , Selenojalpait and Mckinstryit . In the 9th edition , the sulfides are also subdivided according to cations, where stromeyerite can be found together with mckinstryite in a group of sulfides with copper (Cu), silver (Ag) or gold (Au).
In the systematics of minerals according to Dana , stromeyerite and eukairite form a subgroup of sulfides - including selenides and tellurides - with the composition Am Bn Xp, with (m + n): p = 2: 1.
Crystal structure
Stromeyerite crystallizes orthorhombically in the space group Cmc 2 1 (space group no. 36) with the lattice parameters a = 4.06 Å , b = 6.62 Å and c = 7.97 Å as well as 4 formula units per unit cell .
Education and Locations
Stromeyerite mostly forms as a secondary mineral under hydrothermal conditions. Formation as a primary mineral is also possible. The mineral is with Freibergit , bornite , chalcopyrite , galena and other sulphide minerals associated .
So far, stromeyerite has been found at around 300 sites worldwide (as of 2010). In addition to its type locality Vrančice, more precisely in the local "Alexander" mine, the mineral was also found in the Czech Republic near Radětice in Okres Příbram , Jáchymov and in the uranium deposit of the Reichenberg region ( Liberecký kraj ). The largest deposits, however, are in the United States , especially in Arizona , Colorado and Montana .
Well-known sites in Germany are so far Hausach- Hechtsberg and the Clara mine in Baden-Württemberg, Waidhaus- Hagendorf in Bavaria, the Victoria mine in Siegerland (NRW), the Mansfeld Basin in Saxony-Anhalt and Berggießhübel and Freiberg in the Saxon Ore Mountains.
In Switzerland, stromeyerite was found in a drilling carried out by NAGRA near Kaisten in the canton of Aargau, on the Mürtschenalp in the canton of Glarus , in Val Curnera in Graubünden and in the “Les Moulins” pit near Saint-Luc in the canton of Valais.
The only known site in Austria so far is the Erasmus tunnel near Schwarzleo ( Leogang ) in the state of Salzburg.
Other locations include Argentina, Australia, Bolivia, Chile, China, France, Canada, Kazakhstan, Mexico, Norway, Poland and Russia.
use
Stromeyerite is a raw material for the extraction of elemental copper and silver.
See also
literature
- Stromeyerite in: Anthony et al .: Handbook of Mineralogy , 1990, 1, 101 ( PDF 83.8 )
Web links
- Mineral Atlas: Stromeyerite (Wiki)
- mindat.org - Stromeyerite (Eng.)
Individual evidence
- ^ A b c Hugo Strunz , Ernest H. Nickel: Strunz Mineralogical Tables . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p. 65 .
- ↑ Mindat - Number of localities for Stromeyerite
- ↑ Find location list for Stromeyerite at the Mineralienatlas and at Mindat