Mineral: Anglesite
Chemistry: PbSO4
Size: 90 mm
Owner: Mariusz Oleszczuk
Photographer: Mariusz Oleszczuk

A composite crystal of very pale blue anglesite, comprising a "stack" of tabular crystallites that has grown with constant crystallographic orientation. 

The colour of the anglesite is unusual, but is characteristic of a large pocket that was mined in the late 1980s but which, unfortunately, was largely destroyed by blasting, with only a few specimens surviving.  This specimen is believed to be from that pocket, although the location in the mine is not recorded (Anon. 1990).

There is a tacit assumption that the blue colouration in these specimens is related to the presence of copper but analytical confirmation appears to be lacking.