Miharaite

miharaite

wittichenite

bornite

chalcopyrite

Images

Formula: PbCu4FeBiS6
Sulphosalt, bismuth-bearing mineral
Crystal system: Orthorhombic
Specific gravity: 6.06 calculated
Hardness: 4
Colour: Pale grey to greyish-white in reflected light
Environments

Metamorphic environments

Miharaite occurs in skarn, as a product of contact metamorphism (Mindat). Associated minerals include wittichenite, bornite, chalcopyrite and galena (HOM).

Localities

At the type locality, the Honpi deposit, Mihara mine, Higashi-Mihara, Ibara City, Okayama Prefecture, Japan, the deposit is a is a metasomatic bornite-rich skarn deposit of copper. The bornite occurs as disseminations in a hedenbergite-garnet-epidote skarn associated commonly with chalcopyrite. Both miharaite and wittichenite occur both as separate grains and also associated with chalcopyrite and/or galena as small granules or drops (10-30 microns) in the bornite, and sometimes along grain boundaries of bornite as stringers or chains of drops. It is suggested that wittichenite, as well as chalcopyrite, is probably a product of exsolution from a bornite solid solution stable at high temperature. Miharaite occurs only microscopically, generally several tens of microns in size but up to 0.3 mm, as tiny granular drop-like shapes or irregular masses, closely associated with chalcopyrite, galena and sometimes wittichenite (AM 65.784-788).

At the Imooka mine, Kagamino-cho, Tomata District, Okayama Prefecture, Japan, miharaite occurs in a mineralised quartz vein through granite (HOM).

At the Ulsan Mine, Buk District, Ulsan, South Korea, miharaite occurs in a bornite vein in copper skarn ore (HOM).

At the Wedelseie Adit, Konnerudkollen Mines, Konnerud, Drammen, Buskerud, Norway, miharaite has been found as striated, prismatic crystals associated with chalcopyrite, sphalerite and beautiful bipyramidal quartz
(Mindat photo).
Miharaite from the Wedelseie Adit - Image

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