Ferberite (twin) with Marcasite

Item Description

Here is a wonderful miniature specimen of Ferberite from the classic locality at Tasna. This species 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 a classic, "butterfly" twinned crystal of Ferberite showing twinning along the a (100) face. The overall quailty of the twin is good for Tasna, with some sharp faces (some are pretty lustrous), and the classic jet-black color. The piece is associated with spherical groups of metallic golden Marcasite. Twinned crystals from Bolivia have becoming increasingly difficult to obtain in recent years as the price of Tungsten ore has driven the miners to throw 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, and are unlike the specimens from well known localities such as Panasqueira, Portugal and Yaogangxian, China, which are just single blades. You don't see many pieces like this one from Tasna, so if you're in the market for a twinned Ferberite, don't miss out as these are few and far between.