Detailed information
Species
Azurite, Malachite, Anglesite
Dimensions
30 x 85 x 69
mm
Weight
181 g
Locality
Tsumeb Mine Tsumeb, Oshikoto Region Namibia
Condition
No recorded repairs
This small cabinet sized specimen is a superb demonstration of the complex geochemical processes that have taken place within the ore bodies at Tsumeb mine. Three-quarters of the main display face are covered by small (up to 8 or 9 mm across) bladed Azurite crystals, but only a fraction of these remain as glossy deep blue Azurite, most are either fully replaced by velvety green Malachite, or are in an intermediate stage of alteration. The other third, to one quarter of the display surface is a combination of Anglesite (bladed lead sulphate) and Cerussite (platy to tabular lead carbonate) both of which form under the opposite geochemical conditions to each other (acid and alkali). The Azurite and Malachite pseudomorphs after Azurite crystals are mostly in very good condition, with only light abrasion of note. Ex Kessler Collection.