Calcite, (w. Hematite)

Mineral: Calcite, Hematite
Chemistry: CaCO3
Size: 100 mm.
Owner: Geoff Krasnov
Photographer: Geoff Krasnov

Composite, rhombohedral crystals of colourless, glassy calcite (to 40 mm).  Many of the calcite faces are stepped, with the parallel growth "plates" resulting from the alternation of positive and negative rhombohedrons,

The calcite has been preferentially included with minute particles of iron oxide, presumably hematite (?), which accounts for the localised brick-red colour.