Klockmannite
| Klockmannite | |
|---|---|
 |
|
| General and classification | |
| chemical formula | CuSe |
|
Mineral class (and possibly department) |
Sulfides and sulfosalts |
|
System no. to Strunz and to Dana |
2.CA.05 ( 8th edition : II / C.22) 08/02/12/02 |
| Crystallographic Data | |
| Crystal system | hexagonal |
| Crystal class ; symbol | dihexagonal-dipyramidal; 6 / m 2 / m 2 / m |
| Room group (no.) | P 6 3 / mmc (No. 194) |
| Lattice parameters | a = 3.94 Å ; c = 17.25 Å |
| Formula units | Z = 6 |
| Physical Properties | |
| Mohs hardness | 2 to 3 |
| Density (g / cm 3 ) | measured on synthetic material: 5.99; calculated: 6.12 |
| Cleavage | completely after {0001} |
| Break ; Tenacity | not defined |
| colour | slate gray, tapering to black blue |
| Line color | not defined |
| transparency | opaque |
| shine | Metal gloss, matt |
Klockmannite is a rarely occurring mineral from the mineral class of " sulfides and sulfosalts ". It crystallizes in the hexagonal crystal system with the chemical composition CuSe and is therefore chemically a copper selenide, more precisely copper (II) selenide .
Klockmannite is opaque in every form and occurs predominantly in the form of granular mineral aggregates of slate-gray, metallic shimmering color, whereby some of the grains can also take on a thin to thick tabular habit .
Etymology and history
During his time as a professor at the Technical University of Aachen in 1928 , Paul Ramdohr examined, among other things, the type of material stored there of the mineral that Friedrich Klockmann called umangite (Cu 3 Se 2 ) from the Sierra de Umango in the Argentine province of La Rioja . During the ore microscopic analysis, Ramdohr was astonished to find that the material had neither the reddish-violet color nor its composition described as typical for Umangit. Instead of reddish-purple, the mineral showed a slate-like gray-blue color and the composition was determined with CuSe. In addition to the Aachen mineral sample, part of the "umangite" in the collections of the Clausthal Mining Academy also consisted of the substance recognized as a new mineral.
After some deliberation, Ramdohr decided that Klockmann's original description of umangite with the composition Cu 3 Se 2 should continue to exist and chose the name Klockmannite for the new mineral with the composition CuSe on the occasion of Klockmann's 70th birthday.
classification
In the meanwhile outdated, but still in use 8th edition of the mineral classification according to Strunz , the klockmannite belonged to the mineral class of "sulfides and sulfosalts" and there to the department of "(sulfides with the molar ratio) metal: sulfur, selenium, tellurium = 1: 1" , where he formed an independent group together with Covellin , Idait and Nukundamit .
The 9th edition of Strunz's mineral systematics , valid since 2001 and used by the International Mineralogical Association (IMA), assigns klockmannite to the class of "sulfides and sulfosalts (sulfides, selenides , tellurides , arsenides , antimonides , bismuthides , sulfarsenites , sulfantimonites , Sulfbismuthite ) ”and there in the section of“ Metal sulfides, M: S = 1: 1 (and similar) ”. However, this division is further subdivided according to the predominant metal ion in the compound, so that the mineral can be found according to its composition in the sub-division "with copper (Cu)", where together with Covellin, Spionkopit and Yarrowit the "Covelling group" with the System no. .CA.05 forms.
The systematics of minerals according to Dana also assigns the Klockmannite to the class of "sulfides and sulfosalts" and there into the category of "sulfide minerals". Here he is only together with Covellin in the "Covelling group" with the system no. 02.08.12 within the subsection " Sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 1: 1 ".
Crystal structure
Klockmannite crystallizes isotypically with Covellin ( Kupferindig ) in the hexagonal crystal system in the space group P 6 3 / mmc (space group no. 194) with the lattice parameters a = 3.94 Å and c = 17.25 Å as well as six formula units per unit cell .
properties
Klockmannite tarnishes quickly in the air and becomes dull. In reflected light, the mineral shows strong optical anisotropy and strong pleochroism from brownish-gray to gray-white.
Education and Locations
Klockmannite is formed through hydrothermal processes in deposits containing copper and tellurium , where it is mostly found in paragenesis with berzelianite , chalcomenite , clausthalite , crookesite , eukairite and umangite .
As a rare mineral formation, Klockmannite could only be detected at a few sites, with around 60 sites being known to date. In addition to its type locality Sierra de Umango, the mineral was found in Argentina in several places in the province of La Rioja and in the Sierra de Cacheuta in the province of Mendoza .
In Germany, Klockmannite could be found in the Krunkelbach mine near Menzenschwand in Baden-Württemberg, in the Christa mine near Kirchenlamitz - Großschloppen in the Fichtelgebirge and in Wölsendorf ( Schwandorf district ) in Bavaria, at several locations in the Harz Mountains in Lower Saxony and Saxony-Anhalt, near Alberoda in Saxon Ore Mountains and Gera in Thuringia.
The only known site in Switzerland so far is Weierfeld in the Rheinfelden district in the canton of Aargau, where the mineral was discovered in rock samples from a Red Bed deposit from the Permian .
Other locations include the Dianne Mine near Dimbulah in the Australian Shire of Mareeba district ; the El Dragón mine in the Antonio Quijarro province in Bolivia, the flamenco mine in the Chilean region of Atacama (Chañaral), the Yutangba selenium deposit in the Enshi district (Hubei), the Tamusu uranium deposit in the right Alxa banner (Inner Mongolia) and the silver - Luchang-Datongchang copper deposit in Huili County (Sichuan) in China, the Paukkajanvaara mine near Joensuu in Finland, Kruth and Prévinquières (Aveyron) in France, several locations in the Canadian provinces of Ontario , Québec and Saskatchewan , the Shinkolobwe mine in the Democratic Republic Congo (Zaire), the Moctezuma Mine in Mexico; Kletno in Poland, Valdemarsvik and Boliden in Sweden, Bohemia and Moravia in the Czech Republic and Hope's Nose near Torquay in England in the United Kingdom.
See also
literature
- Paul Ramdohr , Hugo Strunz : Klockmann's textbook of mineralogy . 16th edition. Ferdinand Enke Verlag, 1978, ISBN 3-432-82986-8 , pp. 448 .
Web links
Individual evidence
- ↑ Webmineral - Klockmannite
- ^ 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. 76 .
- ↑ a b Klockmannite , In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF 57.8 kB )
- ^ A b Paul Ramdohr: Klockmannite, a new natural copper selenide. In: Centralblatt für Mineralogie, Geologie und Paläontologie. 1928, pp. 225–232 ( PDF 768 kB )
- ^ Helmut Schrätze, Karl-Ludwig Weiner: Mineralogie. A textbook on a systematic basis . de Gruyter, Berlin; New York 1981, ISBN 3-11-006823-0 , pp. 226 .
- ↑ Mineral Atlas: Klockmannite
- ↑ Mindat - Number of localities for Klockmannite
- ↑ Find location list for klockmannite at the Mineralienatlas and at Mindat