Pyrrhotite

The label says “Nova Lima” and my guess is this piece is from the Morro Velho gold mine. This mine was founded in 1725 and became the deepest mine in the world, reaching over 3,000 meters. The gold was in auriferous pyrite, arsenopyrite and pyrrhotite. Specimens were plentiful in the 1960’s but in 1970 mine management prohibited collecting. This survivor is absolutely unique in form. The color is a coppery brass with an adamantine luster that , when played in the light, reveals the almost micaceous layers of growth. Previously in the Terrence Thompson (purchased in 03/96) and formerly in the Dr Hunter collection.

Locality: Nova Lima, Minas Gerais, Brazil

Composition: iron sulfide