Azurite, (on Smithsonite)

Chemistry: Cu3(CO3)2(OH)2
Size: 80 mm
Owner: Harvard University (Karabacek Collection)
Photographer: Malcolm Southwood

Blocky, equant, crystals of lustrous, blue-black azurite (to 9 mm) on an off-white, sub-botryoidal crust of sub-mm smithsonite crystals. The azurite is essentially unaltered although there is just a localised blush of malachite (?) staining on the smithsonite (Photograph 2).  Sparse, reticulated twins of colourless-white cerussite (to 7 mm) are also present on the smithsonite (see close-up photographs; FOV is c. 40 mm for both Photographs 2 and 3).

The specimen is number 1810 in the Karabacek collection, which dates it to the first oxidation zone.

 Courtesy  of  the  Mineralogical  &  Geological  Museum  at  Harvard  University,  Azurite; MGMH  ID# 93552, Tsumeb; Namibia. @ copyright 2012, President and Fellows of Harvard College. All rights reserved.