Adamite , Schultenite Locality: Tsumeb Mine (Tsumcorp Mine), Tsumeb , Otjikoto (Oshikoto) Region, Namibia ( Locality at mindat.org ) Size: miniature, 3.9 x 3.2 x 2.1 cm Schultenite on Adamite var. Cuproadamite Nestled in a vug of massive black ore are gemmy and glassy, bright green crystals of cuproadamite, to .5 cm across. Associated with the cuproadamite are large crystals, to 1.0 cm across, of colorless, glassy and gemmy schultenite: a rare, lead, hydrogen arsenate. This is a VERY VERY rare species! Any specimen should be worht something, and a displayable rich miniature like this is the likes of which I have not seen for sale. The larger shard of schultenite is about 1.5 cm. the Sharper, but smaller complete crystals are about 7 mm. There is a 1 cm cleaved crystal showing a cleavage plane frontally on the bottom, as well. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Schultenite
Schultenite is an IMA-recognized mineral species in the arsenate class, with the chemical formula Pb(AsO₃OH).
It crystallizes in the monoclinic crystal system (space group P2/c).
Key properties: Mohs hardness 2.5; specific gravity 5.94–6.07; White streak; Vitreous to nearly adamantine luster; optically biaxial.
IMA symbol Slt, grandfathered status — known before the IMA’s founding, named in 1926.
A rare secondary mineral found in the oxidized zone of Pb–As-rich hydrothermal deposits.
It is found associated with Anglesite, bayldonite, cuprian adamite, keyite, olivenite, duftite, carminite, beudantite, scorodite, stranskiite, pharmacosiderite, mimetite, cerussite.
The mineral was named to honor Professor August Benjamin Friherre af Schultén (1856–1912), chemist, University of Helsinki, Helsinki, Finland, who studied synthetic arsenates.