Bolivia has probably produced more tin than any other country in the world. The great tin mines at Viloco (sometimes called Araca) have produced some of the most magnificent Cassiterite specimens extant. This piece features sharp, highly lustrous, somewhat gemmy, brown and black color, cyclic twinned Cassiterite crystals associated with small Siderite discs and gemmy Quartz crystals. This specimen was actually mined about 20 years ago when Viloco was really pumping out specimens! 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. The piece is in great shape, and most crystals are virtually damage free, but the large "heart-shaped" twin on the top of the piece is dinged. It is still a great overall display piece. This classic material from Viloco is simply not seen for sale in today's market.