Feather like split calcite crystals

A unique, very aesthetic cabinet size specimen, of split calcite crystals on the base of rhombohedral calcite crystals. The permanent split of the crystals make forms like feathers which are translucent to transparent neer to the end of the aggregate.

Amethyst, calcite, siderite

An outstanding cabinet size specimen of amethyst with dark – indigo color, steep calcite crystal with a slightly dissolved scalenohedral habit, and small crystals of siderite with gold color.

Galena, calcite, sphalerite, chalcopyrite, bornite, covelite

A very interesting specimen, of black sphalerite – marmatite and chalcopyrite, overgrowth by large galena cubic crystals, followed by flat rhombohedral calcite crystals. In the late stage of crystallization, galena was strongly dissolved and some of the crystals are particularly destroyed. Could be seen typical „fingerprint“ dissolution, but the surfaces stay mirror lustrous. Probably the same process was the reason for appearance of „rainbow chalcopyrite surfaces“ – the result of the coating by bornite and covellite.
size 110 x 65 x 50 mm – weight 311,7 grams

Calcite

A perfect cabinet size specimen showing very interesting morphology. One well-developed scalenohedron calcite crystal is overgrowth by several layers of calcite aggregates and at the end of the crystallization process on the scalenohedron were developed several clear flat calcite rhombohedron crystals with lustrous crystals faces.

Calcite, quartz sphalerite

One exceptional specimen , build in small quartz crystals, covered by black sphalerite and overgrowth by calcite aggregate. On the top is situated large, translucent double terminated calcite scalenohedron crystal. What is very rare, is that one of the ends of scalenohedron is twined in a „swallow-tail“ twin.

Needle quartz, galena, pyrite, calcite

One thumbnail specimen of galena and pyrite, followed by thin, transparent quartz needles, in the last stage of crystallization by calcite rhombohedrons and scalenohedrons.