Mineral: Anglesite, Galena
Chemistry: PbSO4
Size: 100 mm
Owner: Harvard University (Karabacek Collection)
Photographer: Malcolm Southwood

Diamond-shaped crystals of anglesite (to 32 mm) have developed in parallel growth in, and on, a sulphide (mainly galena) matrix.   The crystals on the side of the specimen that grew proximal to the sulphide (Photograph 1) are black due to abundant inclusions of relict sulphide, while the other side of the specimen shows colourless-white crystals, one of which is a large (32 mm) colourless individual, gemmy, and almost water-clear.

This is a first oxidation zone specimen, from the Karabacek collection.

Courtesy  of  the  Mineralogical  &  Geological  Museum  at  Harvard  University,  Anglesite; MGMH  ID# 91538, Tsumeb; Namibia. @ copyright 2012, President and Fellows of Harvard College. All rights reserved.