Siglo XX mine, Llallagua, Bustillo Province, Potosi Department, Bolivia.
A nice specimen of vauxite, with somewhat brighter color than most of what has come out recently. This piece was collected around 2011, and was the best piece from a group that I purchased at that time. Like most, this consists of a thin plate of crystals.
The lighter green crystals visible int he closeups are paravauxite.