Chalcocite

Well-formed clustered and single crystals of metallic grey Chalcocite measuring to 1.1 cm are developed over a ferruginous Quartz matrix with a covering of 'granular' Chalcocite, from the North Pig Lode, Geevor mine, Pendeen, Cornwall. The Chalcocite forms as hexagonal tabular crystals with bevelled edges, displaying linear and crazed surface patterns. Unlike some Cornish Chalcocite which has a dull sooty patina, these crystals have a semi-metallic lustre and can produce subtle glimpses of iridescent peacock colours. Some of the Chalcocite crystals are partly twinned. This cabinet specimen was probably mined between 1980 and 1985, with Geevor ending production in 1990. This specimen is accompanied with a detailed previous collector’s label and a former British dealer’s label.