Mineral: Azurite
Chemistry: Cu3(CO3)2(OH)2
Size: 125 mm
Owner: Harvard University (Karabacek Collection)
Photographer: Malcolm Southwood

Blocky, blue-black azurite crystals (to 50 mm) forming sub-parallel to parallel aggregates on a matrix that comprises partly massive azurite, and partly altered dolostone.  The intensely blue colour is quite superb by Tsumeb azurite standards, and appears to have been enhanced - locally, at least - by some incipient natural etching of the crystals.

The specimen is number 4779 in the Karabacek collection, which dates it to the first oxidation zone.

Courtesy  of  the  Mineralogical  &  Geological  Museum  at  Harvard  University,  Azurite; MGMH  ID# 93541, Tsumeb; Namibia. @ copyright 2012, President and Fellows of Harvard College. All rights reserved.