Calcite with Pyrite

This large cabinet specimen of stubby nail head Calcite crystals is from the classic Broken Hill mining district in New South Wales, Australia.  The origin of the orebody is now considered to be a SEDEX deposit (SEDimentary EXhalative), similar to black smokers seen on today’s ocean floors.  This magnificent specimen has a 12.0 x 13.4 cm area of squat, nail head Calcite crystals, all translucent to opaque and dusted with dark tarnished micro-crystals of Pyrite.  The Calcite has a slight pinkish tint, indicating the presence of manganese.  The Pyrite coating is preferentially deposited on crystal faces aligned towards one direction, so indicating the ‘way-up’ when in-situ.  Under LWUV the entire surface of the Calcite fluoresces mild orange.  A great display piece from the phenomenal Broken Hill mines.