cuprite (w. mimetite)

calcite; mimetite

A shard of sulphide matrix hosts vugs containing colourless microcrystals (rhombs) of calcite and larger crystals of cuprite and mimetite. The mimetite presents as tiny individual crystals (<0.5 mm), colourless to very pale yellow, with a tabular hexagonal habit. Locally these form pagoda-like stacks sitting on the sulphide, a few of which are isolated while the majority coalesce to form botryoidal masses which, under magnification resemble cauliflower florets (Exhibit 2). Post-dating (?) the mimetite are modified octohedral crystals of blood-red cuprite (to 4 mm).

The specimen was purchased from Manfred Baumstark in 2014 but with no information on its earlier provenance or location in the mine.