Gallite
| Gallite | |
|---|---|
 |
|
| General and classification | |
| chemical formula | CuGaS 2 |
|
Mineral class (and possibly department) |
Sulfides and sulfosalts |
|
System no. to Strunz and to Dana |
2.CB.10 ( 8th edition : II / C.03) 02.09.01.03 |
| Crystallographic Data | |
| Crystal system | tetragonal |
| Crystal class ; symbol | tetragonal-scalenohedral; 4 2 m |
| Space group | I 4 2 d (No. 122) |
| Lattice parameters | a = 5.35 Å ; c = 10.48 Å |
| Formula units | Z = 4 |
| Twinning | along {112} and {111} |
| Physical Properties | |
| Mohs hardness | 3 to 3.5 |
| Density (g / cm 3 ) | measured: 4.2; calculated: 4.35 |
| Cleavage | is missing |
| colour | Gray |
| Line color | grey black |
| transparency | opaque |
| shine | Metallic luster |
Gallite is a very rare mineral from the mineral class of sulfides and sulfosalts . It crystallizes in the tetragonal crystal system with the chemical composition CuGaS 2 and forms massive grains and lamellae up to two millimeters in size, gray in color and metallic luster .
Etymology and history
The mineral was first found in 1958 by Hugo Strunz , Bruno H. Geier and Erich Seeliger in the Tsumeb mine in Namibia . It was the first known mineral of the rare element gallium and was accordingly named after it.
classification
In the Strunz system , gallite 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 chalcopyrite , eskebornite , laforetite , lenaite and roquesite . In the ninth edition , the sulfides are also subdivided according to cations, where gallite forms chalcopyrite, eskebornite, haycockite , laforêtite, lenaite, mooihoekite , putoranite , roquesite and talnakhite, a subgroup of metal sulfides with a metal to sulfur, selenium or tellurium ratio of 1 : 1 and zinc , iron , copper or silver .
In the systematics of minerals according to Dana , it forms with chalcopyrite, eskebornite, laforetite, lenaite and roquesite the chalcopyrite subgroup of sulfides - including selenides and tellurides - with the composition Am Bn Xp, with (m + n): p = 1: 1 .
Crystal structure
Gallite crystallizes in the tetragonal crystal system in the space group I 4 2 d (space group no. 122) with the lattice parameters a = 5.35 Å and c = 10.48 Å as well as four formula units per unit cell .
Education and Locations
Gallite forms in metal ore deposits with a relatively high proportion of gallium. It is associated with renierite , germanite , bornite , chalcosine , diginite , pyrite , sphalerite , galena and tetrahedrite .
In addition to the Tsumeb mine, there are also finds from Kipushi in the Democratic Republic of the Congo , Pazardschik in Bulgaria , Pinar del Río in Cuba and Yauricocha in Peru .
See also
literature
- Gallite in: Anthony et al .: Handbook of Mineralogy , 1990, 1, 101 ( pdf )
Web links
Individual evidence
- ^ A b c Hugo Strunz , Ernest H. Nickel : Strunz Mineralogical Tables. Chemical-structural Mineral Classification System . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p. 77 .
- ↑ a b c Gallite. In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America, 2001 ( PDF 59.7 kB ).
- ↑ Stefan Weiß: The large Lapis mineral directory. All minerals from A - Z and their properties . 5th completely revised and supplemented edition. Weise, Munich 2008, ISBN 978-3-921656-70-9 .
- ↑ a b Mindat - Gallite