About
"Peacock Ore" which is sold to many amateur mineral collectors often as a variety of Bornite, is in fact almost always Chalcopyrite treated with acid to produce an iridescent tarnish. Though some Chalcopyrite is naturally iridescent, wild colors such as strong blues and purples are usually formed from acid treatment.
Crystal Forms & Aggregates
Other ID Marks
Complex Tests
Striking Features
Environment
Varieties
✓ common · ✗ uncommon
- Blister Copper— Chalcopyrite in a globular or botryoidal rounded form.
- Peacock Ore— Term used to describe Chalcopyrite or Bornite with a colorful iridescent tarnish effect, usually artificially enhanced with acid. Most Peacock Ore is sold as Bornite, when in fact it usually produced from acid-treating Chalcopyrite.
Uses
Noteworthy Localities
Many fine Chalcopyrite crystals occur in Zacatecas Mexico; Concepción del Oro and San Martín are noteworthy. The Huaron Mine in Cerro del Pasco, Peru is also a classic locality.
In the U.S., the Tri-state district of Kansas, Oklahoma, and Missouri has provided the important Chalcopyrite localities of Joplin, Jasper Co., Missouri; Picher, Ottawa Co., Oklahoma; and Treece, Cherokee Co., Kansas. The Sweetwater Mine, Reynolds Co., Missouri produces small sparkling crystals, with some having a natural blue iridescence. Other excellent Chalcopyrite occurrences are the Gilman District, Eagle Co., Colorado; Ouray, Ouray Co., Colorado; and Ellenville, Ulster Co., New York. The Chimney Rock Quarry in Bound Brook, Somerset Co., New Jersey, has produced unique reniform blobs; and the the French Creek Mine in Chester Co., Pennsylvania has produced large distorted and highly tarnished crystals that are highly sought after by collectors.
Common Mineral Associations
Distinguishing Similar Minerals
Gold - Nonbrittle, much heavier (15.5 - 19.3).
Bornite - Usually darker in color, more tarnish.
Photos
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