Bournonite with Quartz

A terrific specimen of Bournonite finely displaying its characteristic “cog wheel” crystals set amongst inter-meshed sheaves of micro-crystalline Quartz after baryte. Bournonite from the Herodsfoot mine at Lanreath near to Liskeard in Cornwall, England, is one of the true Cornish classic minerals. A roughly cubic block of mixed massive Bournonite and milky-Quartz is capped with castellated ridges of well crystallised Bournonite of steely-grey colour, blushed with peacock-blue iridescence. The “cogs” are well defined and occur as individual crystals and connected ribbed plates. The Quartz is also typical of that found at Herodsfoot in that it crystallises over pseudomorphs of platy Baryte. A splendid example of Bournonite with Quartz from the world famous Herodsfoot Mine in Cornwall.