Olivenite crystals from the Tsumeb Mine, Otavi Mountains, Namibia, Ilse Baer collection – micromount as unique piece
This micromount specimen with Olivenite crystals from the Tsumeb Mine, Otavi Mountains, Namibia originates from the Ilse Baer collection and was collected before 1972. The specimen shows a dark matrix covered with numerous fine Olivenite crystals that give the surface a distinctly crystalline texture.
The Olivenite crystals occur in dense groups of small crystals displaying the typical green to olive colored tones of the mineral. At the top of the specimen a compact group of dark, lustrous crystals is present, creating a strong visual contrast to the green Olivenite coating and adding an additional mineralogical highlight to this micromount specimen.
Geology & Origin
Olivenite is a copper arsenate hydroxide and is a typical secondary mineral of the oxidation zone of polymetallic deposits. It forms through the weathering of arsenic bearing copper ores under oxidizing conditions. The Tsumeb Mine in Namibia is one of the most important classic mineral localities in the world and is famous for its extraordinary diversity of rare secondary copper and lead minerals formed by complex geochemical processes in the oxidation zone.