Cook's Kitchen mine near Camborne was a famous mid-18th century copper mine which, like many in Cornwall, transitioned to tin during the 19th century due to zonation with the orebodies, with copper near surface and tin at depth. In its early years it was famous for fine mineral specimens of species that were unusual for their time, such as bubbly, brassy Blister Copper (Chalcopyrite), but also excellent pseudohexagonal crystals of grey metallic Chalcocite. This very large miniature specimen is richly covered in small (up to 4 mm) but well-defined hexagonal prisms of Chalcocite presenting a lovely dark bluish-grey colour with surface iridescence. These crystals sit, freestanding, upon a layer of orange-pink Quartz which is itself a layer within sulphide-Quartz veinstone which makes up the base of the specimen. The matrix contains the occasional quite large tarnished cube of Pyrite and much copper sulphide showing small golden cores of Chalcopyrite altering to purplish Bornite and grey Chalcocite. The copper sulphide mineralogy in this piece is possibly far more complicated than meets the eye, with a chance that the fine, free-standing Chalcocite crystals are in fact partially replaced by Bornite, or Covelline.
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