Kësterite

kesterite

stannite

sphalerite

pyrite

Images

Formula: Cu2ZnSnS4
Sulphide, stannite group, zinc- and tin- bearing mineral, forms a series with stannite
Crystal System: Tetragonal
Specific gravity: 4.54 to 4.59
Hardness: 4½
Streak: Black
Colour: Greenish black
Environments

Hydrothermal environments

Kësterite occurs in quartz-sulphide hydrothermal veinlets in tin deposits. Associated minerals include arsenopyrite, stannoidite, chalcopyrite, chalcocite, sphalerite and tennantite (HOM).

Localities

At the Snowflake mine, Mount Cotterell, Revelstoke Mining Division, British Columbia, Canada, an example of a stannite-kësterite intergrowth was found. The ore consists chiefly of sphalerite, pyrite and galena, with lesser, but appreciable, amounts of stannite-kësterite; the remainder of the minerals occur in very small to trace amounts, and include cassiterite, pyrrhotite, rutile, scheelite, silver-bearing tetrahedrite, chalcopyrite, covellite, cerussite and a tellurium-bearing canfieldite.
The stannite-kësterite occurs as black, coarsely crystalline masses, up to 2 inches across, associated with pyrite in a matrix of milky quartz, apparently of vein-type origin. All fragments of stannite-kësterite mounted in polished sections exhibit exsolution textures (CM 11.531-534).

The type locality is the Kester deposit, Kester harpolith, Arga-Ynnakh-Khaya granite Massif, Yana-Adycha Region, Yana River Basin, Verkhoyansk District, Sakha, Russia.

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