Kharaelakhit
| Kharaelakhit | |
|---|---|
| General and classification | |
| other names |
IMA 1983-080 |
| chemical formula | (Pt, Cu, Pb, Fe, Ni) 9 S 8 |
|
Mineral class (and possibly department) |
Sulphides and sulphosalts - metal sulphides, M: S> 1: 1 |
|
System no. to Strunz and to Dana |
2.BB.15 ( 8th edition : II / B.17) 07/02/05/01 |
| Similar minerals | Mackinawit , Godlevskit |
| Crystallographic Data | |
| Crystal system | orthorhombic |
| Crystal class ; symbol | orthorhombic-dipyramidal; 2 / m 2 / m 2 / m , orthorhombic pyramidal; mm 2 or orthorhombic-disphenoidal; 222 |
| Space group | Pmmm (No. 47) , Pmm 2 (No. 25) or P 222 (No. 16) |
| Lattice parameters | a = 9.71 Å ; b = 8.33 Å; c = 14.50 Å |
| Formula units | Z = 4 |
| Physical Properties | |
| Mohs hardness | not defined |
| Density (g / cm 3 ) | calculated: 7.78 |
| Cleavage | not defined |
| colour | Gray |
| Line color | not defined |
| transparency | opaque |
| shine | not defined |
| Crystal optics | |
| Pleochroism | strong, purple to blue |
Kharaelakhite is a very rare mineral from the mineral class of " sulfides and sulfosalts ". It crystallizes in the orthorhombic crystal system with the chemical composition (Cu, Pt, Pb, Fe, Ni) 9 S 8 . The elements copper , platinum , lead , iron and nickel indicated in the round brackets can represent each other in the formula ( substitution , diadochie), but are always in the same proportion of 9: 8 to sulfur .
Kharaelakhite forms elongated crystals up to 120 μm in size and gray in color. Thin flags are also known on Braggit .
Etymology and history
Kharaelakhit was founded in 1985 by AD Genkin et al. found on the Taimyr Peninsula in northern Russia . The mineral is named after its type locality , the Kharaelakh plateau.
Type material of the mineral is stored in the Fersman Museum (catalog No. 84282) and in the mineralogical laboratory of the Geological Institute of Ore Deposits, Petrography, Mineralogy and Geology in Moscow .
classification
In the meanwhile outdated, but still in use 8th edition of the mineral classification according to Strunz , the kharaelakhite belonged to the division of "Sulphides, Selenides and Tellurides with a molar ratio of metal: S, Se, Te> 1: 1", where it was found together with Godlevskit , Horomanit , Mackinawit and Sugakiit formed the unnamed group II / B.17 .
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 classifies kharaelakhite in the category of "Metal sulfides, M: S> 1: 1 (mainly 2: 1)". This is, however, further subdivided according to the predominant metals in the compound, so that the mineral, according to its composition, can be found in the sub-section "with rhodium (Rh), palladium (Pd), platinum (Pt) etc.", where it is the only one Member forms the unnamed group 2.BC.70 .
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the kharaelakhite to the class of “sulphides and sulphosalts” and there to the category of “sulphide minerals”. Here he is the only member of the unnamed group 07/02/05 within the subsection “ Sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 9: 8 ”.
Crystal structure
Kharaelakhite crystallizes in the orthorhombic crystal system with the space group Pmmm (space group No. 47) , Pmm 2 (No. 25) or P 222 (No. 16) , the lattice parameters a = 9.71 Å , b = 8.33 Å and c = 14.50 Å, as well as four formula units per unit cell .
Education and Locations
Kharaelakhite is formed from chalcopyrite under hydrothermal conditions . It is associated with this as well as Braggit, Bornite and Millerite . Apart from its type locality and another find in the vicinity, no other occurrences are known.
See also
literature
- Aleksandr Dmitrievich Genkin, TL Evstigneeva, LN Vyalsov, IP Laputina: Kharaelakhite (Pt, Cu, Pb, Fe, Ni) 9 S 8 - a new sulfide of platinum, copper and lead . In: Mineralogicheskiy Zhurnal . tape 7 , 1985, pp. 78-88 (Russian).
- John L. Jambor: New Mineral Names . In: American Mineralogist . tape 74 , 1989, pp. 1215-1220 ( minsocam.org [PDF; 733 kB ; accessed on January 28, 2017]).
Web links
- Mineral Atlas: Kharaelakhite (wiki)
- mindat.org - Kharaelakhite (English)
- Webmineral - Kharaelakhite (English)
Individual evidence
- ^ A b 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. 70 .
- ↑ a b Kharaelakhite . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 ( handbookofmineralogy.org [PDF; 60 kB ; accessed on January 29, 2017]).