Ferberite

Unknown Owner

Large, thick, tabular to bladed lustrous grey-black Ferberite (iron tungstate) crystals are intergrown as an open diverging crystal group with individual crystals reaching 5 cm across, on a matrix of Arsenopyrite. The Tazna mine in southern Bolivia is renowned for the world's finest twinned Ferberite crystals and although this cabinet-sized display piece is not dominated by twins, it does present excellent intergrown bladed crystals. Minor chipping is noted to some crystals around the periphery, which is reflected in the price, but this is undoubtedly still an extremely fine crystallized Ferberite. As always with tungsten-bearing minerals this piece has a really dense, heavy feel to it. Ex Professor Werner Paar Collection.