CassiteriteCassiterite is rarely seen in faceted stones as the material if often not transparent enough to cut fine stones, plus it requires a skilled cutter to properly handle the brittle material. Bolivia has probably produced more Cassiterite ore than any country in the world. The large majority of the Cassiterite from Viloco is completely opaque and black. Rarely, gem quality crystals are found and those that escape the crusher are prized for their clarity.

A VERY rarely seen Ferberite twin on matrix from Tasna

1 cm across sitting beautifully on the underlying Quartz matrix

especially with crystals like this from Bolivia

and Creedite is certainly one of the most elusive

and when you throw in the fact that it's completely undamaged

which is due to their smaller size

as the piece is 100% crystallized on all sides

or any other world locality

crystallized

This amazing “nail head”-shaped crystal was caused due to hydrothermal etching in the pocket after the crystal had formed

It hosts a few

Matrix specimens are rare from Tomokoni