|
COBALTITE , a See also: mineral with the composition CoAsS, See also: cobalt sulpharsenide
.
It is found as granular to compact masses, and frequently as beautifully See also: developed crystals, which have the same symmetry as the isomorphous mineral See also: pyrites, being cubic with parallel hemihedrism
.
The usual forms are the See also: cube, octahedron and pentagonal dodecahedron {210}
.
The colour is See also: silver-See also: white with a reddish tinge, and the lustre brilliant and metallic, hence the old name cobalt-glance; the streak is greyish-black
.
The mineral is brittle, and possesses distinct cleavages parallel to the faces of the cube; hardness 51; specific gravity 6.2
.
The brilliant crystals from Tunaberg in Sodermanland and Hakansboda in Vestmanland, Sweden, and from Skutterud near
See also: Drammen in See also: Norway are well known in mineral collections
.
The cobalt ores at these localities occur with pyrites and chalcopyrite as bands in See also: gneiss
.
Crystals have also been found at Khetri in See also: Rajputana, and under the name sehta the mineral is used by See also: Indian jewellers for producing a blue enamel on gold and silver ornaments
.
Massive cobaltite has been found in small amount in the Botallack mine, See also: Cornwall
.
A variety containing much iron replacing cobalt, and known as ferrocobaltite (Ger
.
Stahlkobalt), occurs at See also: Siegen in Westphalia
.
(L
.
J . |
|
|
[back] COBALT (symbol Co, atomic weight 59) |
[next] COBAN, or SANTO DOMINGO DE COBAN |
There are no comments yet for this article.
Do not copy, download, transfer, or otherwise replicate the site content in whole or in part.
Links to articles and home page are encouraged.