Bolivia008 - Franckeite and Franckeite var. Potosíite - San José Mine, Oruro City, Cercado Province, Oruro Department, Bolivia

Extremely rich specimen of these two rare tin sulphosalts with crystals to 4 mm. The specimen is essentially a floater mass of crystals with no matrix; some of the crystals are twinned. Potosíite is a Sn(II)-poor variety of franckeite once thought to be a separate species. 7.7 x 4.6 x 2.6 cm.