Briartite
| Briartite | |
|---|---|
| General and classification | |
| other names |
IMA 1965-018 |
| chemical formula | Cu 2 (Fe, Zn) GeS 4 |
|
Mineral class (and possibly department) |
Sulfides and sulfosalts |
|
System no. to Strunz and to Dana |
2.KA.10 ( 8th edition : II / C.06) 02.09.02.03 |
| Crystallographic Data | |
| Crystal system | tetragonal |
| Crystal class ; symbol | tetragonal-scalenohedral; 4 2 m |
| Room group (no.) | I 4 2 m (No. 121) |
| Lattice parameters | a = 5.32 Å ; c = 10.51 Å |
| Formula units | Z = 2 |
| Physical Properties | |
| Mohs hardness | 4.5 |
| Density (g / cm 3 ) | calculated: 4.337 |
| Cleavage | Please complete |
| colour | gray, also gray-blue in incident light |
| Line color | Please complete |
| transparency | Please complete |
| shine | Please complete |
Briartite is a very rarely occurring mineral from the mineral class of " sulfides and sulfosalts ". It crystallizes in a tetragonal crystal system with the chemical composition Cu 2 (Fe, Zn) GeS 4 and thus the zinc analogue of barquillite (Cu 2 (Cd, Fe) GeS 4 ). The elements iron and zinc indicated in round brackets can represent each other in the formula ( substitution , diadochie), but are always in the same proportion to the other components of the mineral.
Briartite is opaque in every form and has a gray, in incident light also gray-blue color. So far it could only be found in the form of small grains up to about two millimeters in diameter and as an inclusion in other sulfides.
Etymology and history
Briartit was first discovered in the "Kipushi Mine" (also "Prince Léopold Mine") near Kipushi in the Democratic Republic of the Congo. It was described in 1965 by J. Francotte, R. Moreau, R. Ottenburgs and C. Lévy, who named the mineral after Gaston Briart , who studied the Kipushi deposit.
classification
In the meanwhile outdated, but still in use 8th edition of the mineral classification according to Strunz , the Briartite belonged to the mineral class of "sulfides and sulfosalts" and there to the department of "sulfides with the molar ratio of metal: sulfur, selenium, tellurium ≈ 1: 1", where together with barquillite , černýit , famatinite , ferrokësterite , hocartite , kësterite , kuramite , luzonite , permingeatite , petrukite , pirquitasite , rhodostannite , sakuraiite , stannite , toyohaite and velikite, the "stannite group" with the system no. II / C.06 formed.
The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), also assigns Briartite to the class of "sulfides and sulfosalts", although there it belongs to the "sulfarsenates" category. This division is further subdivided according to the crystal structure, so that the mineral can be found according to its structure in the subdivision of the “sulfarsenates with (As, Sb) S 4 tetrahedra”, where it can be found together with barquillite, famatinite, luzonite and permingeatite "Luzonit Group" with the system no. 2.KA.10 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns Briartite to the class of "sulphides and sulphosalts" and there in the category of "sulphide minerals". Here he is together with Hocartite, Barquillite, Černýit, Ferrokësterit, Kësterit, Kuramit, Pirquitasit, Sakuraiit, Stannit and Velikit in the "stannite group (tetragonal: I 4 2 m ) A 2 BCS type" with the system no. 02.09.02 within the subsection " Sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 1: 1 ".
Education and Locations
Briartite is a rare inclusion in other germanium-gallium-containing sulphides. As accessory mineral occur among other chalcopyrite , galena , germanite , Renierit , sphalerite and Tennantit on.
In addition to its type locality "Kipushi Mine" (also "Prince Léopold Mine") in the Democratic Republic of the Congo, the mineral was previously (as of 2012) in the "Plan d'Argut" deposit near Argut-Dessous in the Haute-Garonne and department near Bancaïroun ( Guillaumes ) in the Alpes-Maritimes department in France, in the "Kamariza Mines" near Agios Konstantinos in the Greek region of Attica , in the " Tsumeb Mine" in Namibia, in the "Kabwe Mine" (also known as the "Broken Hill Mine") ) at Kabwe in Zambia, the “Teresita Mine” near Riosa and the Barquilla Sn-Ge-Cd-Cu-Fe deposit near Salamanca in Spain and the “Inexco Mine” near Jamestown in the US state of Colorado .
Crystal structure
Briartite crystallizes tetragonally in the space group I 4 2 m (space group no. 121) with the lattice parameters a = 5.32 Å and c = 10.51 Å as well as 2 formula units per unit cell .
See also
literature
- J. Francotte, R. Moreau, R. Ottenburgs, C. Lévy (1965): La briartite, Cu 2 (Fe, Zn) GeS 4 , une nouvelle espèce minérale , in: Bulletin de la société française minéralogie et de cristallographie , volume 87 (1965), pp. 432-437
Web links
- Mineral Atlas: Briartite (Wiki)
Individual evidence
- ↑ a b c d e 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. 79 .
- ↑ Webmineral - Briartite
- ↑ a b John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols: Briartite , in: Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF 61.4 kB )
- ↑ Mindat - Briartite