Ferberite (twin) with minor Jamesonite
- Tasna mine, Rosario section of Cerro Tasna, Nor Chichas Province, Potosi Department, Bolivia
- Miniature, 4.6 x 3.8 x 3.6 cm
- Start Time: 10/01/2009 6:45:00 pm (CDT)
- End Time: 10/08/2009 6:45:00 pm (CDT)
- Auction Closed
A superb twinned crystal of Ferberite from the renowned Tasna mine in southern Bolivia. The piece was mined at the beginning of 2008, which is encouraging because I have seen VERY little in the way of Ferberites from this mine in recent years. Ferberite was sometimes previously referred to as "Wolframite", which was supposed to be an intermediary species between Ferberite and Hubnerite, but has since been discredited. This piece features the classic, "butterfly" twinning of Ferberite along the a (100) face. It is a good quailty, sharp, lustrous, aesthetic jet-black twinned crystal with associated botryoidal Marcasite and small acicular crystals of grey Jamesonite. It has an attractive thick blocky form, and is a wonderful miniature size specimen. Twinned crystals from Bolivia are becoming increasingly difficult to obtain in recent years as the price of Tungsten ore has driven the miners to throw nearly all the Ferberite into the crusher, causing thousands of specimens to be lost forever. These twins are definitely the most highly sought after crystal habit from this locality. This piece is one of the better formed Ferberite twins that I have offered in a while, due to the fact that it is complete on the top and the bottom, and not cleaved like so many others from this mine. Valued at $800-$1000.