Mineral · Sulfides
Bornite
Cu5FeS4
Bornite is copper iron sulfide, bronze-brown on a fresh surface and tarnishing rapidly to purple and blue, the original 'peacock ore'. Crystals are rare (Butte, Montana; Dzhezkazgan); massive bornite from Mexico and Kazakhstan is the usual specimen. Most peacock ore in shops is treated chalcopyrite, not bornite.
| Formula | Cu5FeS4 |
|---|---|
| IMA status | grandfathered |
| Crystal system | Orthorhombic |
| Mohs hardness | 3 |
| Group | Sulfides |
| Type locality | None |
| Streak | Greyish black |
| Specific gravity | 5.1 |
| Reference list | IMA List of Minerals (RRUFF) — verify formula and status against the current list |
Elsewhere
Cite this article
Stratum Study. "Bornite" (Mineral). Stratum Study pack 2026.09, as of 2026-09-19. https://stratum.black/study/minerals/bornite. Accessed 2026-09-20.
@misc{stratum-bornite,
title = {Bornite},
author = {{Stratum Study}},
howpublished = {\url{https://stratum.black/study/minerals/bornite}},
year = {2026},
note = {Mineral article, Stratum Study pack 2026.09, as of 2026-09-19; sources: stratum, wikidata, commons. Accessed 2026-09-20.}
} Citations carry the pack version and the article's as-of date so they resolve to the same text later. The facts themselves belong to the sources listed below; cite those for the science.