Ranciéite, Goethite
Marble quarry, Olsa, Friesach, Sankt Veit an der Glan District, Carinthia, Austria
Photomicrograph of violet ranciéite crystals in a veinlet of colloform goethite (with a radial fibrous structure), over a thin black manganese oxide coating (hollandite and minor braunite), from Friesach, Carinthia, Austria.
This material was described in:
Ertl, A., Pertlik, F., Prem, M., Post, J.E., Kim, S.J., Brandstätter. F., and Schuster, ...
© Andreas Ertl, University of Vienna, Austria