Babánekite - new arsenate from Jáchymov

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Created on Saturday, 14 July 2012 19:11

Last Updated on Saturday, 14 July 2012 19:18

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Babánekite is next new mineral phase described in the first hlaf of the year 2012 from the world most varied locality - Jáchymov. New minerals described in last years has usually obsure chemical composition or new structure type, that is why recent description of babánekite is possible to consider as anomaly. It is the simple member of the vivianite group like e.g. erythrite, annabergite and so on.

Its idealized chemical composition is Cu₃(AsO₄)₂ * 8H₂O. Its very strange that such a simple chemical compound was not described for a very long time before. This fact has probably several reasons, one of the main fact is, that is is probably rare on most part of localities. The other reason is probably due to its appearance. Babánekite is very similar to the other member of the vivianite group - erythrite. It is because all specimens we studied had always several procents of cobalt, which has very good colouring ability. We dont know chemically "clear" babánekite, so we dont know its "right" colour at this time.

That is why, when you would like to buy some "babánekite" specimen in future, there will be always necessary to document the chemical composition by its analyse.

The type specimens caming out from the Rovnost shaft from the III Geisterlauf level. It occured here in limited amount in association with minerals of lindackerite group, lavendulan and zeunerite in cavities of primary Ni, Co minerals historically called "Speisse".

Co-type specimen of babánekite from Jáchymov, Rovnost shaft, III Geister level. FOV 3 mm.

Literatura:

Plášil*, J., Fejfarová, K., Radek Škoda, R., Škácha, P., Sejkora, J., Veselovský, F., Hloušek, J., Novák, M. (2012) Babánekite, IMA 2012-007. CNMNC Newsletter No. 13, June 2012, page 814; Mineralogical Magazine, 76, 807-817.