Fluorite with Calcite

A magnificent cabinet specimen of colourless to pale lilac-green, almost spherical Fluorite crystals with a preferential coating of tiny white Calcite crystals.  This is from the Naica mine at Mun. de Saucillo in Chihuahua, Mexico, famous for its gigantic gypsum crystals in various caverns such as ‘Cave of Swords’ and ‘Cave of the Crystals’.  The Fluorite crystals show octahedral growth but are modified to complex geometries as a result of temperature-pressure conditions and restrictions in accommodation space.  The largest crystal visible amongst the complex jumble is about 3 cm, while overall they probably average 2 cm in diameter.  A great aesthetic specimen and a good and rare example of this form of epitaxial crystal growth.  All the Fluorites are transparent tending to gemmy and occasionally contain small inclusions of Chalcopyrite.