olivenite (w. malachite)

A block of massive malachite hosting vugs lined with velvety, mammilary surfaces of dark green malachite, supplanted by acicular crystals (exceptionally to 20 mm) of translucent lighter green olivenite. Exhibit 2 shows a closer view of the olivenite crystals. This habit of olivenite is seldom seen in modern collections and appears to have been encountered only in the upper levels of the first oxidation zone.

This is specimen number 1050 in the collection of Wilhelm Klein and his handwritten catalogue (unpublished) confirms that it was collected from the Tsumeb open pit. Klein was a senior manager at Tsumeb between 1916 and 1939.

A very similar specimen is preserved in the Kegel Collection held at the Smithsonian (catalogue number NMNH R8600).

malachite