Location: Sweetwater Mine, Viburnum Trend, Reynolds County, Missouri, USA

Size: 2.1 x 1.7 x 0.5 inches

Nice brassy colored crystals on a dolomite matrix. The slight iridescence on this piece is naturally occurring due to conditions in the mine.

Chalcopyrite is a copper iron sulfide mineral and the most abundant copper ore mineral. It is frequently confused with pyrite and sometimes even gold since all three of these minerals have a similar color and luster. A characteristic that helps distinguish Chalcopyrite and pyrite is that Chalcopyrite is much softer than pyrite and can be scratched with a knife.

Sometimes called “Peacock Ore” which is actually another Bornite so not technically correct but has been commonly used to describe pieces of Chalcopyrite that have vivid colors.

NOTE: Most specimens of chalcopyrite that have a bright blue or purple iridescence, including this one, were treated with acid to enhance their visual appeal. I do carry other pieces of chalcopyrite that have not been altered by man (it occasionally occurs in nature) by a similar process.