Roger Weller, geology instructor
email@example.com copyright 2010-R.Weller
Bornite, a copper iron sulfide, is also known as peacock ore. On a freshly broken
surface the mineral has a metallic luster and almost a copper metal color. Upon
prolonged exposure to air, the mineral tarnishes in a beautiful way. The small
grains of bornite in the photo below show purples, blues, reds, and greens as the
tarnish develops. Often there are metallic yellow grains of chalcopyrite present with
the massive bornite. Because of the high reflectivity of the metallic luster, it is often
difficult to photograph all of the colors.
Photos are copyright free only for non-commercial educational uses.
Just credit photos to R.Weller/Cochise College.