Associated species include cerussite, chalcomenite and olsacherite.
It was described by Palache (1937) as an acicular, white oxidation product of penroseite, and by Ahlfeld and Munoz Reyes (1955) as occurring with ahlfeldite, chalcomenite and olsacherite in cavities in decomposed penroseite.
Chalcomenite is a hydrated copper selenite formed as an oxidation product of penroseite.
Chalcomenite occurs as acicular crystals up to 3 mm long which are transparent with a blue color and a green tint, on penroseite and cavernous limonite.
Associated minerals are: a second new selenite, [Pb.sub.4]Cu[Cl.sub.3]-[(Se[O.sub.3]).sub.3](OH), chalcomenite
(up to 2 cm long!), atacamite, pseudoboleite, chlorargyrite, olsacherite, mandarinoite, schmiederite, francisite, clausthalite-galena, galena, covellite and arsenopyrite.
The alteration of these minerals has yielded rare selenites of copper (chalcomenite
, CuSe[O.sub.3].2[H.sub.2]O) and of cobalt (cobaltomenite).
From the type locality of the copper selenide berzelianite, Skrikerum in southeastern Sweden, several selenium-bearing minerals have been newly identified: athabascaite, bukovite, umangite and chalcomenite
are the additional phases.
, kerstenite and other rare selenium minerals from the El Dragon mine, Potosi, continue to be available, and at the 1995 Tucson Show, both Rock Currier and Gary Nagin (Crystal Springs Mining Company, PO.