Provenite

About Bornite

Cu₅FeS₄

A copper-iron sulfide with about 63% copper, known as peacock ore for the iridescent purple and blue tarnish that quickly forms on its copper-red to brown fresh surfaces. Well-formed crystals are uncommon; most bornite is massive ore.

Show 11 localities on the map

Photos of Bornite

Tree-like cluster of thick, elongated bornite crystals from the Carn Brea Mine.
Bornite · Carn Brea Mine
Tree-like cluster of thick, elongated bornite crystals from the Carn Brea Mine.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Close-up of bornite crystals from the Dzhezkazgan Mine, field of view 9 mm.
Bornite · Dzhezkazgan Mine (Zhezkazgan)
Close-up of bornite crystals from the Dzhezkazgan Mine, field of view 9 mm.
Photo: Leon Hupperichs · CC BY-SA 3.0 · Source
Cluster of sharp dodecahedral steel-gray bornite crystals on quartz from Butte.
Bornite · Butte Mining District
Cluster of sharp dodecahedral steel-gray bornite crystals on quartz from Butte.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Three large discrete bornite crystals on a quartz plate from the Leonard Mine.
Bornite · Leonard Mine
Three large discrete bornite crystals on a quartz plate from the Leonard Mine.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Iridescent massive bornite on matrix from the Cole Mine, Bisbee.
Bornite · Cole Mine (Cole shaft), Bisbee
Iridescent massive bornite on matrix from the Cole Mine, Bisbee.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Bornite from the Kupferschiefer of the Thomas Muentzer shaft, Sangerhausen, field of view 20 mm.
Bornite · Thomas Muentzer Shaft (Schacht Sangerhausen)
Bornite from the Kupferschiefer of the Thomas Muentzer shaft, Sangerhausen, field of view 20 mm.
Photo: Leon Hupperichs · CC BY-SA 3.0 · Source
Chalcopyrite crystals coated with bornite on epidote from the Dashkesan deposit.
Bornite · Dashkesan Co-Fe deposit
Chalcopyrite crystals coated with bornite on epidote from the Dashkesan deposit.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Large piece of massive bornite with gold, blue and purple iridescence from the Lavender Pit, Bisbee.
Bornite · Lavender Pit
Large piece of massive bornite with gold, blue and purple iridescence from the Lavender Pit, Bisbee.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source

Where Bornite is found (11)

Azerbaijan

Germany

Kazakhstan

Peru

United Kingdom

United States

Bornite on the same specimen with other minerals

Same specimen Bornite with Sphalerite at Butte Mining District

2 specimen photo(s) from this locality show sphalerite with bornite together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Bornite with Siderite at Aggeneys

1 specimen photo(s) from this locality show siderite with bornite together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Bornite at Dzhezkazgan Mine (Zhezkazgan)

2 specimen photo(s) from this locality show bornite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Bornite at Carn Brea Mine

1 specimen photo(s) from this locality show bornite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Pyrite with Bornite at Butte Mining District

1 specimen photo(s) from this locality show bornite with pyrite together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Bornite at Butte Mining District

1 specimen photo(s) from this locality show bornite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Quartz with Bornite at Leonard Mine

2 specimen photo(s) from this locality show bornite with quartz together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Chalcopyrite with Bornite at Huarón Mine (Huarón Mining District)

1 specimen photo(s) from this locality show bornite with chalcopyrite together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Pyrite with Bornite at Huarón Mine (Huarón Mining District)

1 specimen photo(s) from this locality show bornite with pyrite together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Same specimen Chalcopyrite with Bornite at Dashkesan Co-Fe deposit

1 specimen photo(s) from this locality show bornite with chalcopyrite together. The pairing comes from the photographer's file name and label, so the relationship between the two minerals is not specified.

Identity

Also called
peacock ore; peacock copper
Strunz
2.BA.10 · 2 Sulfides and sulfosalts
IMA status
Grandfathered
Name origin
Named in 1845 in honour of the Austrian mineralogist Ignaz Edler von Born (1742-1791).
Elements
Cu, Fe, S

Physical properties

Color
Copper-red to pinchbeck-brown on fresh surfaces; tarnishes rapidly to iridescent purple and blue
Streak
Pale grayish black
Luster
Metallic luster
Transparency
Opaque
Mohs hardness
3–3.25
Density
5.06–5.08 g/cm³
Cleavage / fracture
Cleavage on {111} in traces; fracture uneven to subconchoidal; brittle
Magnetism / fluorescence
Magnetic after heating; non-fluorescent

Crystallography

Crystal system
Orthorhombic
Space group
Pbca
Structure
Pseudocubic orthorhombic superstructure; a = 10.950, b = 21.862, c = 10.950 Å, Z = 16. Intermediate and high-temperature forms exist above the stability field of the low form.
Typical habit
Pseudocubic, dodecahedral or octahedral crystals up to 6 cm; most commonly granular, compact, massive or disseminated
Twinning
On {111}; penetration twins common
Optical data
Opaque; pinkish brown in polished section when fresh; weak but noticeable pleochroism; weak anisotropy

Formation and use

Formation
Disseminated in mafic igneous rocks, in contact-metamorphic skarns, in pegmatites, in medium- to high-temperature hydrothermal deposits and in sedimentary cupriferous shales; the low form is stable below about 200 °C. Associated with chalcopyrite, pyrite, other Cu-Fe sulfides, garnet, calcite, wollastonite and quartz.
Uses
Important ore of copper; collector specimens.
Stability and care
Fresh surfaces tarnish rapidly to iridescent purple and blue colours.

Related minerals

Related minerals
Digenitechalcopyrite

Sources

  1. SRC-664 · Book
    Handbook of Mineralogy - BorniteAnthony, J.W.; Bideaux, R.A.; Bladh, K.W.; Nichols, M.C. · 2005 · Mineral Data Publishing / Mineralogical Society of America
  2. SRC-665 · Database
    Bornite Mineral DataBarthelmy, D. · Webmineral.com
  3. SRC-666 · Website
    BorniteWikipedia contributors · Wikipedia

Draft data from the Provenite workbook. Check entries against the cited sources before relying on them. Photos are open-licence images from Wikimedia Commons; the author and licence are given with each photo.