Nekrasovite
| Nekrasovite | |
|---|---|
| General and classification | |
| other names |
IMA 1983-051 |
| chemical formula | Cu 26 V 2 (Sn, As, Sb) 6 S 32 |
|
Mineral class (and possibly department) |
Sulfides and sulfosalts |
|
System no. to Strunz and to Dana |
2.CB.30 ( 8th edition : II / C.10) 01/03/01/03 |
| Crystallographic Data | |
| Crystal system | cubic |
| Crystal class ; symbol | 4 3 m |
| Space group | P 4 3 n |
| Lattice parameters | a = 10.73 Å Please complete the source as an individual reference |
| Formula units | Z = 1 Please complete the source as an individual reference |
| Physical Properties | |
| Mohs hardness | 4.5 |
| Density (g / cm 3 ) | 4.62 |
| Cleavage | Please complete |
| colour | reddish brown |
| Line color | Please complete |
| transparency | opaque |
| shine | Please complete |
Nekrasovit is a very rarely occurring mineral from the mineral class of sulfides and sulfosalts . It crystallizes in the cubic crystal system with the chemical composition Cu 26 V 2 (Sn, As, Sb) 6 S 32 and forms round grains up to 1 μm in size and red-brown in color.
Etymology and history
The mineral was first found in 1984 by VA Kolavalenker, TL Evstigneeva, VS Malov, NV Trubkin, AI Gorshkov and VR Geinke in the Khayragach gold deposit in the Chatkal and Qurama Mountains (eastern Uzbekistan ). They named it after the Russian mineralogist Ivan Yakovlevich Nekrasov.
classification
In the Strunz system , Nekrasovite is counted among the metal sulfides with a ratio of metal to sulfur, selenium or tellurium of 1: 1. After the 8th edition , it forms a group together with colusite , germanite , maikainite , morozeviczite , germanocolusite , ovamboite , polkovicit , renierite , stibiocolusite , sulvanite and vinciennite . In the 9th edition , it forms a subgroup of sulfides with zinc , iron , copper or silver with colusite, germanite, maikainite, germanocolusite, ovamboite and stibiocolusite .
In the Dana systematics , it forms the colusite group with colusite, germanocolusite and stibiocolusite, a subgroup of sulfosalts with the composition (A + ) i (A 2+ ) j [B y C z ] (A: metals, B: semi-metals, C . Non-metals) and the ratio of z / y> 4.
Education and Locations
Nekrasovite forms in ores in andesite and dacite . It is associated with tetrahedrite , tennantite , luzonite , famatinite , pyrite , mawsonite , chalcopyrite , emplectite , laitakarite , bismuth , calcite , quartz and barite .
Only seven sites (as of July 2010) are known of the very rare mineral. In addition to its type locality , Nekrasovit was found in Massa in Italy , Shiribeshi and Shimoda in Japan , and in Bisbee in the US state of Arizona .
Crystal structure
Nekrasovit crystallizes in the cubic crystal system in the space group with the lattice parameter a = 10.73 Å and one formula unit per unit cell .
See also
Individual evidence
literature
- Nekrasovit in: Anthony et al .: Handbook of Mineralogy , 1990, 1, 101 ( pdf ).