Calcite, (on Dolomite)

Mineral: Calcite, Dolomite
Chemistry: CaCO3
Size: 78 mm
Owner: Mariusz Oleszczuk
Photographer: Mariusz Oleszczuk

Flattened rhombs of snow-white calcite (to 15 mm) on a contrasting druse of brownish-red dolomite.

The calcite crystals have a slightly frosted appearance, perhaps due to natural etching, but they have been partly overgrown by a later generation of composite, water-clear calcite rhombs (see Photograph 2; FOV 35 mm). 

The colour of the dolomite is assumed to be due to the presence of iron oxides.