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Bornite – Peacock Ore / Peacock Copper

Filed under: Mineral of the day,Reader submissions- Rockhound stores,Video — Gary September 21, 2010 @ 7:51 pm

Bornite is a sulfide mineral with chemical composition Cu5FeS4 that crystallizes in the orthorhombic system.  Also called ‘the stone of happiness‘.

Peacock Ore

Peacock Ore

Appearance

Bornite has a brown to copper-red color on fresh surfaces that tarnishes to various iridescent shades of blue to purple in places. Its striking iridescence gives it the nickname peacock copper or peacock ore. As this appearance can not always be naturally found, many sellers of peacock ore dip the mineral in acid to accentuate the colors.

Mineralogy

Bornite is an important copper ore mineral and occurs widely in porphyry copper deposits along with the more common chalcopyrite. Chalcopyrite and bornite are both typically replaced by chalcocite and covellite in the supergene enrichment zone of copper deposits. Bornite is also found as disseminations in mafic igneous rocks, in contact metamorphic skarn deposits, in pegmatites and in sedimentary cupriferous shales. It is important as an ore for its copper content of about 63 percent by mass.

Bornite

Bornite / Peacock Copper

Occurrence

It occurs globally in copper ores with notable crystal localities in Butte, Montana and at Bristol, Connecticut in the U. S. It is also collected from the Carn Brea mine, Illogan, and elsewhere in Cornwall, England. Large crystals are found from the Frossnitz Alps, eastern Tirol, Austria; the Mangula mine, Lomagundi district, Zimbabwe; from the N’ouva mine, Talate, Morocco and in Dzhezkazgan, Kazakhstan.

History and etymology

It was first described in 1725 for an occurrence in the Krušné Hory Mountains (Erzgebirge), Karlovy Vary Region, Bohemia in what is now the Czech Republic. It was named in 1845 for Austrian mineralogist Ignaz von Born (1742–1791).

Interesting Video about Bornite-

A reader submitted a question to me and this was the first thing that came to mind (Peacock Ore).  Anyone want to try and answer (story and question below)-

So I live in Utah and spend much time in the mountains and also work on a mountain range.
I came across an old miners bouillon. It looked out of place so I exposed the rest of it. The outside appeared to be shaped like a bowl ( I later found out it was a cauldron) so of course, ya keep it.
It sparked an interest, I had heard of stories of an old sheepherder from Spain that spent his summers there on the hill.
The man was rich back in Spain.
Sparked an interest….what was he doin in Utah herding sheep for 20 years.
So I was on a mission.
I came across a spot on the mountain with rock that was a rhyolite that I had not seen before, so I looked around. Turns out there is a vein of rhyolit that was inside some quartzite rocks that someone has been chipping and taking the vein, replacing the outcropping rocks with the rocks that were around the vein to make it look as if noone was there.
By the look of things someone had been doing this for some time.
I happened to grab some of this vein and it is beautiful multi colored and heavy as hell.
I need info on how to identify the already cooked bouillon that I found. Any help!!

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