Bournonite

This solid, ex-matrix mass of graphite-grey Bournonite crystals is from Les Malines Mining District, Saint-Laurent-le-Minier, Gard, France and is typical of the large cog-wheel crystallised groups for which this locality is famous.  Individual crystals reach 2.5 cm in length and develop in the familiar stellate pattern of heavily ribbed faces from where the term ‘cog-wheel’ ore derives.  Les Malines District is the largest lead-zinc deposit in France and is of hydrothermal origin, termed a ‘stratiform deposit’ because of its sedimentary-like layers.  A superb Bournonite that will make a terrific display piece and highly representative of this French locality.