BRIARTITE with CATAMARCAITE, THALCUSITE BORNITE (Polished Section)

SPECIMEN DESCRIPTION

Eight chips of metalliferous vein material from La Rosario mine, Capillitas mining district, Argentina are mounted in a polished block where they are visible on a cut and polished surface. These chips contain a wealth of extremely rare species, including two primary germanium-bearing species: Briartite and Catamarcaite; along with a thallium-bearing mineral - Thalcusite. The other main mineral present is Bornite but this pales into insignificance compared to the other rarities. There are very few germanium-bearing mineral species known to science and La Rosario mine is one of the few places where they occur in significant amounts. Catamarcaite was first described from Capillitas in 2006, and has never been found anywhere else on Earth. Briartite is a little more 'common', having been reported from 15 localities, but recent studies appear to suggest that this material from Capillitas is a new species Zincobriartite but the full details are awaiting publication. A fine assemblage of extreme rarities but as with all polished ore sections reflected light microscopy is really required to appreciate them.