Chemistry:Trogtalite

From HandWiki
Trogtalite
Oosterboschite, Trogtalite, Cuprosklodowskite, Quartz-384830.jpg
Piece of oosterboschite with cuprosklodowskite, quartz, and brown oxidized trogtalite from the Musonoi mine. From the Howard Belsky collection.
General
CategorySelenide minerals
Formula
(repeating unit)
CoSe2
Strunz classification2.EB.05a
Dana classification2.12.1.5
Crystal systemCubic
Crystal classDiploidal (m3)
H-M symbol: (2/m 3)
Space groupPa3
Identification
ColorRose-violet
Crystal habitIrregular grains
Mohs scale hardness3.5-5.5
|re|er}}Metallic
DiaphaneityOpaque
Density7.12 (calculated) 7.09 (synthetic)
PleochroismNone
Ultraviolet fluorescenceNone
SolubilityInsoluble
Common impuritiesCu, Pd
References[1][2][3]

Trogtalite is a rare selenide mineral with the formula CoSe2. It crystallizes in the cubic system and is part of the pyrite group, consisting of Co2+ and Se22− ions. It has a rose-violet colour and its crystals are opaque.[1] It often occurs as grains. It was thought to be dimorphous with hastite, but this was discredited in 2009.[2] Hastite turned out to be the iron selenide mineral ferroselite.[3] It forms a solid solution series with krut'aite.

Occurrence

Trogtalite was first found in 1955 in Trogtal quarry, Lautenthal, Harz Mountains, Germany , after which it was also named. It often occurs intergrown with clausthalite grains at this locality. It has also been found in the Musonoi Cu–Co mine, Kolwezi, Katanga Province, Congo and in Argentina , in Tuminico, Sierra de Cacho, and in Los Llantenes, La Rioja Province. It is often found together with clausthalite, ferroselite, bornhardtite, native selenium, gold, and oosterboschite.[4]

See also

References