Siglo Veinte Mine (Siglo XX Mine; Llallagua Mine; Catavi), Llallagua, Rafael Bustillo Province, Potosi Department, Bolivia
Toenail, 2.8 x 2.1 x 1.1 cm
Vauxite is known in many forms and colors from Siglo XX, and this piece shows some of the darkest blue Vauxite that one will see, especially in smaller crystals. The piece hosts a few layered crystal groups of deep blue color Vauxite blades which are sitting on a thin "wash" of white botryoidal Wavellite on matrix. It is very difficult to obtain Vauxite crystals on matrix from this locality, and as you can see, the Vauxite aggregates are simply gorgeous under magnification. The color is about as deep as it gets for the species. One does not see many Vauxites with this color on the market, especially in well-crystallized specimens on MATRIX. Ex. Brian Kosnar.