The uranium deposit at Rožná was discovered in 1954, production started five years later in 1959. The Rožná mine field includes the Bukov, Habři, Milasín, Rozsochy and Rožná mines, with 10 or even more shafts. Up to date informations are difficult to get, but the mine should still be active in 2014. In 2008 it reached a depth of 1200 m on 24 levels. Besides the uranium ore and its secondaries, the mine is famous for the selenide mineralization.
The Rožná deposit lies in the northeastern part of the Moldanubian domain of the Bohemian Massif. Mineralization is of the late Variscan and post-Variscan hydrothermal type and took place in several stages. The selenides were deposited in the uranium ore forming phase, while the copper minerals belong to the post ore and post uranium phase. Host rock alteration with hematite belongs to the pre-uranium phase, the goethite alteration was part of the ore forming phase.
Some remarks on the samples: the specimen were acquired from several sources and in general, never contained the mineral stated on the label. So if you buy material from Bukov it is likely from there but the minerals might be anything until proper analyzed.
The polished sample with Nic //, Obj. 20x, air, 100 µm scale bar. Chalcocite intergrowth with bornite in calcite matrix (with polysynthetic twinning):
Bornite, chalcocite and covellite. Nic //, Obj. 20x, air, 100 µm scale bar:
Chalcopyrite and bornite, the cracks are filled with hematite. Nic //, Obj. 20x, air, 100 µm scale bar:
Chalcopyrite, bornite. Nic //, Obj. 20x, air, 100 µm scale bar:
Goethite, hematite and bornite. Nic //, Obj. 20x, air, 100 µm scale bar:
Same as above with Nic. +. Red: hematite, yellow: goethite:
Covellite, digenite (lighter blue than covellite) in bornite with some chalcopyrite. The cracks are filled with hematite. Nic //, Obj. 20x, air, 100 µm scale bar:
Covellite lamellae in bornite from the foto above. Nic //, Obj. 50x, air, 50 µm scale bar:
For further informations on the region this article might be interesting:
Kříbek: The Rožná uranium deposit (Bohemian Massif, Czech Republic): shear zone-hosted, late Variscan and post-Variscan hydrothermal mineralization. Mineralium Deposita 44 (2009) 99-128