Cassiterite with Tourmaline (rare association) (ex Brian Kosnar Collection)

Item Description

The great tin mine at Viloco (sometimes called Araca) has produced some of the most magnificent Cassiterite specimens extant, and a very small percentange of these pieces are actually associated with rarely seen TOURMALINE! This particular specimen hosts several, fine quality, sharp, highly lustrous, gemmy, golden brown to black cyclic twinned crystals of Cassiterite with individual twins measuring up to 2.1 mm across associated with very small acicular greenish-black crystals of Tourmaline! This association is seen in only a handful of Cassiterite specimens from this historic loaclity. This is a very attractive piece and one of the better ones for quality, luster and crystal size that I've seen in recent years. Very little damage around the periphery but in great shape overall. I have to stress that the luster and sharpness on these Cassiterite crystals is very good, as well as the gemminess on some crystals, which is NOT common in Bolivia. Of all of the tin mines in Bolivia, Viloco is the only one to produce gem quality Cassiterites. That combined with the very hard to find Tourmaline association, this piece is certainly special, and worthwhile for any collector. From the collection of Brian Kosnar. Valued at $1,250.