Calcite, (w. Duftite)

Mineral: Calcite, Duftite
Chemistry: CaCO3
Size: 82 mm
Owner: Geoff Krasnov
Photographer: Geoff Krasnov

A group of colourless-white rhombohedral calcite crystals (to 42 mm) with inclusions of duftite and iron oxides (possibly hematite ?).

Closer examination reveals that an early generation of scalenohedral calcite has been partly overgrown by duftite and iron oxides.  Calcite crystallisation then resumed, covering the first generation crystals (and overgrowths) with rhombohedral calcite crystals.  

The cleaved rhombohedral crystal at left of centre on the specimen reveals the earlier iron oxide coated scalenohedral cross section.