Dims: 1.10x0.78x0.65" (2.80x1.98x1.65cm)
Wt: 0.51oz (14.4g)
Cerro Rico de Potosi, Bolivia
This dull black rock is host to both a matting of fine translucent valentinite crystals and several clusters of fibrous yet transparent valentinite crystals. The latter are quite rare, as they are large enough to examine, at least with a 15x loupe! There is also a non-crystalline white crust present, which I believe is not valentinite, and is difficult to differentiate except with a loupe which reveals the fine individual crystals in a mat-like array of valentinite.