Cassiterite (fine gemmy twinned crystals)

Item Description

Bolivia is well-known for its tin mines, and the primary source of that tin comes in the form of Cassiterite. The famed Viloco Mine (Araca) has produced what are inarguably the finest examples of Cassiterite from the entire country. There are certainly hundreds of places in Bolivia where Cassiterite has been found, but most people don't realize that the ONLY mine to produce gem quality crystals is Viloco. This piece is a fantastic large miniature / small cabinet featuring excellent quality, very sharp, rather lustrous, cyclic twinned crystals measuring up to 1.1 cm across, associated with gemmy/translucent, colorless Quartz crystals on matrix. Many of the Cassiterite crystals are rather gemmy when backlit, showing a mixture of colors ranging from black to a soft golden-buff shade to nearly colorless in some spots. The vast majority of the Cassiterites are in excellent condition, with only small nicks in a few spots. My favorite feature of the specimen is the wonderful twin sitting at the top of the piece with a broad glassy face and an almost "heart"-like habit of twinning. A very eye-catching and fine quality example of these truly classic Cassiterites. Valued $1,250 for size, quality and overall visual beauty. From the collection of Brian Kosnar.