Adamite, (v. cobaltoan adamite)

Mineral: Adamite, Malachite
Chemistry: Zn2(AsO4)(OH)
Size: 105 mm
Owner: Harvard University (Karabacek Collection)
Photographer: Malcolm Southwood

A druse of well-terminated adamite crystals (to 7 mm) covers an entire side of this specimen.  The colour of the terminations is a dark brownish-green. However, the broken surfaces at the edges and ends of the specimen show the rose-pink to plum colours believed to be attributable to the cobalt in this variety of adamite.  Malachite is present as a minor associate.

This is very rare material from the first oxidation zone at Tsumeb, and a fine example. Specimen number 4318 in the Karabacek collection.

Courtesy  of  the  Mineralogical  &  Geological  Museum  at  Harvard  UniversityAdamite; MGMH  ID# 93828, Tsumeb; Namibia. @ copyright 2012, President and Fellows of Harvard College. All rights reserved.