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 particular specimen consists of an exceptionally large, fine, sharp, lustrous, dark brown color, cyclic twinned crystal measuring 3.6 cm across plus several smaller equal quality crystals of Cassiterite and minor Quartz to form a fantastic (and highly displayable) crystal group. This is a very attractive piece and features one of the largest crystals I've seen from this mine in years. There are few small nicks on this specimen, but it features an amazingly large crystal for this great old classic locality. This classic material from Viloco is simply not seen for sale in today's market. Ex. Brian Kosnar.