- Tazna Mine (Tasna Mine; Tazna-Rosario Mine), Cerro Tazna, Atocha-Quechisla District, Nor Chichas Province, Potosi Department, Bolivia
- Toenail, 3.0 x 2.1 x 1.7 cm
Here is a superb, twinned crystal of Ferberite. This piece features the classic, "butterfly" twinning of Ferberite along the (100) face. This piece is a good sized, sharp, lustrous, aesthetic jet-black twinned crystal that is displayable from several angles. Admittedly, there is a very small amount of damage to this crystal, but it is such a great, "textbook" twin, the damage is really forgivable. Twinned crystals from Bolivia have become increasingly difficult for me to obtain from Bolivia. These are definitely the most highly sought after crystal habit from this locality as well.