Name: Ferberite ps. Scheelite on matrix
Brand: The Arkenstone
Price: 500 USD
Availability: InStock

Ferberite ps. Scheelite on matrix

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These are one of the rarest of the rare of old USA classics, particularly of pseudomorphs. We had never seen one on matrix for sale, though loose crystals are a staple of old collections assembled in the early to mid 1900s, and in museums. Not a particularly attractive piece, however, it is very interesting mineralogically as it is a complete pseudomorph of Ferberite after Scheelite. The complete Scheelite pseudomorph is almost black with its good octahedral form preserved. The black-gray, pseudo-octahedral pseudomorph crystal has good luster and measures 1.5 cm in maximum dimension. It is set right near the apex of the iron-stained Quartz matrix and is about three-quarters exposed. Chemically, the original Scheelite is a calcium tungstate and Ferberite is an iron tungstate, so there has been a replacement of iron for calcium while leaving the tungsten/tungstate as part of the composition. Very cool! Part of an educational set, with these additional items: Ferberite with Quartz (SYP25-04a) and Scheelite on Quartz (SYP25-04c).