Calcite, (w. Duftite)

Mineral: Calcite, Duftite
Chemistry: CaCO3
Size: 91 mm
Owner: Geoff Krasnov
Photographer: Geoff Krasnov

An elongated group of intergrown, colourless-white calcite rhombs (to 16 mm) appears to have formed - initially, at least, - over a stalactite-like structure of duftite (?).  This central duftite (?) structure is now hollow, and can be measured to extend at least 17 mm into the calcite (see Photograph 2).

The calcite crystals are themselves dusted with a second generation of duftite (?), which has affected different crystal faces to varying degrees. Some of this later duftite (?) occurs as near-surface inclusions in the calcite, while some of it occurs actually on the crystal surface.