Chalcopyrite var. Blister Copper

I think most collectors of Cornish minerals have a “thing” about Blister Copper. Despite sometimes being a bit ugly they exude an intrinsic fascination, probably from their unique combination of form, colour and often a real toady resemblance (as in toad, not today!). Blister copper is the botryoidal habit of Chalcopyrite and is best known in Cornwall from Cook’s Kitchen mine, now incorporated into the South Crofty complex. However, Blister Copper did occur in several other localities, this miniature being from Levant mine at Trewellard close to St. Just. Composed entirely of Chalcopyrite, it is a fairly heavy specimen for its size. The display face is a smooth, gently undulating surface with flattened hemispheres up to around 1 cm diameter. The patina is that of burnished dull golden brass, with silky lustred gold highlights on the mounds and a dull, velvety lustre in the troughs. A beautiful Blister Copper form of Chalcopyrite from Levant mine, a mine which extended out beneath the Atlantic Ocean.