Bornite “Peacock Ore” Specimen — Iridescent Blue, Purple & Gold, 80g — Field Find

THE FIND
A bornite specimen, 80g — electric blues, purples, and golds shifting across a metallic surface that changes with every angle. Known in the mineral trade as “peacock ore,” this is one of the most visually striking copper minerals available as a display specimen.

WHAT WE KNOW
Bornite is a copper iron sulfide mineral (Cu₅FeS₄) and an important copper ore. Fresh bornite surfaces are bronze to copper-colored, but the mineral oxidizes rapidly on exposure to air, developing the characteristic iridescent tarnish — blues, purples, golds, and greens — that gives it the “peacock ore” trade name. The iridescence is a thin-film optical effect produced by the oxidation layer on the surface, similar to the effect seen on oil films or soap bubbles. Note: the iridescent surface is a tarnish layer and can be affected by handling, moisture, and abrasion. This specimen weighs 80g. Locality not independently verified.

THE STORY
The “peacock ore” name is applied to two different minerals in the trade — bornite and chalcopyrite — both of which develop iridescent tarnish surfaces. Bornite specifically produces the deepest blues and purples in its tarnish layer. The optical physics are the same as a soap bubble: a thin transparent film produces interference colors that shift with viewing angle and film thickness. In bornite, that film is copper oxide, and the colors it produces are among the most vivid in mineralogy.

WHY WE CHOSE IT
The iridescence on this piece is strong and varied — blues, purples, and golds are all present and shift clearly with the viewing angle. At 80g it has enough surface area to display the full color range. A visually immediate specimen that photographs exceptionally well.

ABOUT THIS PIECE
Type: Bornite (“peacock ore”, copper iron sulfide)
Weight: 80g
Locality: Not independently verified
Condition: Natural specimen with iridescent tarnish surface — handle with care to preserve the oxidation layer. Please review photographs for color range and natural variation.
Quantity: 1 — one of a kind.