What does bornite mean?
Bornite is a naturally occurring copper iron sulfide mineral, with the chemical formula Cu₅FeS₄, valued primarily as an important ore of copper. Freshly broken surfaces are pinkish to reddish brown, but when exposed to air the mineral quickly tarnishes, producing a striking iridescent film of purple, blue, and green — an effect so distinctive that specimens are sold commercially under the nickname 'peacock ore'. Bornite typically forms in hydrothermal veins and contact-metamorphic deposits alongside other copper sulfides such as chalcopyrite, and it occurs in significant quantities in major copper-mining regions worldwide. In scientific writing the word appears mostly in mineralogy, geology, and economic geology, while collectors and lapidary enthusiasts encounter it frequently in catalogs and museum displays. Because of its vivid coloration and ready availability, bornite remains one of the most visually recognizable minerals, prized both for display and for the industrial role it plays in supplying copper for wiring, plumbing, and alloys.
nounBornite is a reddish-brown copper iron sulfide mineral, Cu₅FeS₄, that tarnishes on exposure to air to form an iridescent purple-blue surface, earning it the popular name 'peacock ore'. It is an important ore of copper found in many hydrothermal and contact-metamorphic deposits.
- A copper iron sulfide mineral, Cu₅FeS₄, occurring in reddish-brown crystals that tarnish to an iridescent purple-blue, mined as an important ore of copper and known popularly as peacock ore.
"The museum case held a gleaming chunk of bornite, its surface shimmering with purple and blue iridescence."
"Prospectors identified the deposit largely by the unmistakable iridescent sheen of weathered bornite on the rock face."
"Because bornite contains both copper and iron in sulfide form, it smelts readily into metal used for wiring and alloys."
As a mass-noun mineral term, 'bornite' usually appears uncountable when referring to the substance itself; the plural 'bornites' is used mainly when referring to multiple distinct specimens or occurrences.
"The dealer's tray held several fine bornites from mines across three continents."
Nicknamed 'peacock ore' for the dazzling purple-blue tarnish it develops in air, bornite is one of the flashiest minerals in any rock collection — and one of the world's most important sources of copper.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of bornite
Bornite was named in honor of Ignaz von Born, an eighteenth-century Austrian mineralogist and metallurgist who was prominent in scientific circles of his era. Like many mineral species, it was given an eponymous name commemorating a figure who contributed to the study of ores and metals. The '-ite' suffix is the standard ending used in English mineral nomenclature to denote a distinct mineral species. As a result, bornite belongs to the large family of minerals whose names honor individual scientists rather than deriving from Latin or Greek roots.
How bornite is actually used
Bornite is a technical term used chiefly in geology, mineralogy, mining, and among mineral collectors; it rarely appears in everyday speech. The informal trade name 'peacock ore' refers to the same mineral and is more widely recognized outside scientific contexts. Both British and American usage treat it identically.
Easily confused with bornite
Chalcopyrite (CuFeS₂) is a brass-yellow copper sulfide that can develop a similar iridescent tarnish, but it has a different chemical composition and crystal structure than the reddish-brown bornite.
Barite is a soft, heavy white barium sulfate mineral whose similar spelling to bornite often causes confusion, though the two minerals are unrelated in composition and appearance.