Altait
| Altait | |
|---|---|
 |
|
| General and classification | |
| chemical formula | PbTe |
|
Mineral class (and possibly department) |
Sulfides and sulfosalts |
|
System no. to Strunz and to Dana |
2.CD.10 ( 8th edition : II / C.15) 08/02/01/03 |
| Crystallographic Data | |
| Crystal system | cubic |
| Crystal class ; symbol | cubic hexakisoctahedral; m 3 m |
| Room group (no.) | Fm 3 m (No. 225) |
| Lattice parameters | a = 6.439 Å Please complete the source as an individual reference |
| Formula units | Z = 4 Please complete the source as an individual reference |
| Physical Properties | |
| Mohs hardness | 2 to 3 |
| Density (g / cm 3 ) | 8.19 |
| Cleavage | completely after {100} |
| Break ; Tenacity | small mussel |
| colour | tin white |
| Line color | black |
| transparency | opaque |
| shine | metallic |
Altaite (outdated tellurium lead , chemically lead telluride ) is a rarely occurring mineral from the mineral class of sulfides and sulfosalts . It crystallizes in the cubic crystal system with the chemical composition PbTe and usually forms masses up to one centimeter in size, rarely small cubic or octahedral crystals of tin-white color.
Etymology and history
The mineral was first found and described in 1829 by Gustav Rose as part of the expedition through Russia led by Alexander von Humboldt in the Zavodinskoi mine in the Altai Mountains (now Kazakhstan ). He initially called it tellurium lead . Wilhelm Ritter von Haidinger renamed it in 1845 and gave it its current name after the place where it was found in the Altai Mountains, as no other sites were known at the time.
classification
In the Strunz system , Altait 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 the unnamed group II / C.15 with alabandin , Clausthalit , Crerarit , Galenit , Keilit , Niningerit and Oldhamit . In the ninth edition , the sulfides are also subdivided according to cations, where Altaite can be found with these minerals as well as cuboargyrite and schapbachite in the subdivision of metal sulfides with tin , lead , mercury and others.
In the systematics of minerals according to Dana it forms with alabandin, clausthalite, borovskite , crerarite, galenite, keilite, niningerite and oldhamite also the galena group (isometric: Fm3m) as a subgroup of sulphides - including selenides and tellurides - with the composition A m B n X p , with (m + n): p = 1: 1.
Education and Locations
Altaite forms in veins containing gold and tellurium under hydrothermal conditions. It is associated with gold, silver , antimony , tellurium, Tellurantimon , galena , pyrite , Hessit , Nagyagit , tetrahedrite , Sylvanit , petzite , Calaverit , arsenopyrite , sphalerite , chalcopyrite , Jamesonit , Boulangerit , Bournonit , Aguilarit , pyrrhotite , siderite , Cerussit and Quartz .
A total of 280 locations (as of August 2010) of the Altait are currently known. In addition to the type locality , the mineral was found in Sǎcǎrîmbu in Romania , Kalgoorlie in Australia , Fiji , Negros Occidental in the Philippines , Kirkland Lake in the Canadian province of Ontario and the US states of Colorado , North Carolina , Montana , New Mexico , California and among others Minnesota .
Crystal structure
Altait crystallizes in the cubic crystal system with the space group Fm 3 m with the lattice parameter a = 6.439 Å and four formula units per unit cell (sodium chloride structure). Other minerals of this structure type are clausthalite (lead selenite, PbSe), galena (PbS) and alabandin (manganese sulfide, α-MnS).
See also
Individual evidence
- ↑ Nikolai Iwanovitsch Kokscharow: materials on the mineralogy of Russia. 1. Volume, St. Petersburg 1853, ISBN 978-1-1458-6562-4 , pp. 186–188 ( limited preview in Google book search).
- ^ List of minerals according to Dana at webmineral.com
- ↑ Altait at mindat.org (Eng.)
literature
- Altait in: Anthony et al .: Handbook of Mineralogy , 1990, 1, 101 ( pdf ).
