Bornite

Crystal system · Orthorhombic

Bornite is a sulfide mineral known for its striking metallic crystals, with several world-class Chinese localities.

About Borniteextended article

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China is a defining locality for Bornite · 斑铜矿. See the Chinese collector page →

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Collector tier: Solid Display
Reliable mid-tier display species. Easy to find in well-formed examples; broad locality diversity.
Mohs 3
Vickers (~) 170 HV
Knoop (~) 185 HK
Geological setting
Hydrothermal
Element composition by mass

Formula: Cu₅FeS₄ · molar mass: 501.82 g/mol

Cu 63.32%
S 25.56%
Fe 11.13%

Computed from atomic weights (IUPAC 2021). Site-occupancy groups (Fe,Mn) split equally.

Optical Effects
Iridescent
Mohs Hardness 3

Bornite sits at 3 on the Mohs scale — can be scratched by a steel knife.

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Colors:
Streak
Greenish-black
Crystal system
Orthorhombic (low-T) / Cubic (high-T)
Type localityMt. Cornwall, England (and Bohemian mining districts)
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Sulfides & SulfosaltsSulfides
TL;DR · 1 min read
Bornite (Cu₅FeS₄) is one of the most vivid copper sulfides and a major copper ore. Fresh surfaces show a bronze-pink metallic color, but the mineral rapidly tarnishes to vivid iridescent purple, blue, and gold — the famous "peacock ore" effect treasured by collectors.
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Bornite (Cu₅FeS₄) is one of the most vivid copper sulfides and a major copper ore. Fresh surfaces show a bronze-pink metallic color, but the mineral rapidly tarnishes to vivid iridescent purple, blue, and gold — the famous “peacock ore” effect treasured by collectors. It is closely associated with chalcopyrite in porphyry copper deposits and frequently forms exsolution intergrowths with it.

Notable Chinese Localities #

Dexing Copper Mine (Jiangxi) and Daye District (Hubei) produce bornite as porphyry-copper byproducts. Tongling (Anhui) hosts smaller but high-iridescence specimens.

Test at home — what scratches what
Will scratch your specimen:
🪙 Copper coin (US penny) (Mohs 3.5) · 🔪 Steel pocket knife (soft steel) (Mohs 5) · 🥃 Glass plate (Mohs 5.5) · 🔧 Steel file / hardened steel (Mohs 6.5) · ⚙ Sharp steel needle / quartz scratch (Mohs 7) · 🪨 Topaz scratch test (Mohs 8)
Your specimen will scratch:
👆 Talc dust (Mohs 1) · 💅 Fingernail (Mohs 2.5)

Always test on an inconspicuous edge first. Save the test for unimportant specimens — better to use a streak plate or knowledge of locality + paragenesis.

Cite this entry
APA
MyMineralBox Editorial Team. (2026). Bornite. My Mineral Box. Retrieved May 23, 2026, from https://mymineralbox.com/mineral-encyclopedia/minerals/bornite/
MLA
MyMineralBox Editorial Team. "Bornite." My Mineral Box, 2026, https://mymineralbox.com/mineral-encyclopedia/minerals/bornite/. Accessed May 23, 2026.
Chicago
MyMineralBox Editorial Team. "Bornite." My Mineral Box. Last modified May 4, 2026. https://mymineralbox.com/mineral-encyclopedia/minerals/bornite/.
BibTeX
@misc{mmb_bornite,
 author = {{MyMineralBox Editorial Team}},
 title = {{Bornite}},
 year = {2026},
 publisher = {My Mineral Box},
 url = {https://mymineralbox.com/mineral-encyclopedia/minerals/bornite/},
 urldate = {2026-05-23}
}

Identification & care

Specimens usually show cubic, dodecahedral, octahedral crystals (rare); usually massive or granular. Its color is typically copper-red to pinchbeck-brown. The luster is metallic, the streak is grey-black, and specimens are typically opaque. The cleavage is poor/indistinct on {111}. The fracture is irregular/uneven, which aids identification.

Collector context

How it forms

The geological setting for Bornite is typically hydrothermal copper deposits, porphyry copper systems, contact metasomatic zones; frequently found as exsolution product with chalcopyrite. It is commonly found in association with chalcopyrite, chalcocite, pyrite, galena, covellite, native copper.

Classic Chinese localities

**Jiama Cu-polymetallic deposit**, **Dexing Cu-Mo-Au ore field** and **Huanggang Fe-Sn deposit** are an important Chinese source for the species.

Why collectors care

Bornite is among the most visually dramatic sulfides and native metals a collector can own. Bright metallic faces, sharp crystal geometry, and good matrix contrast make a single well-selected piece carry an entire cabinet; luster integrity and termination sharpness ultimately define its collector value.

What affects value

Value in Bornite is assessed, in typical order of weight, against: (1) locality provenance; (2) crystal size; (3) termination quality and crystal completeness; (4) metallic luster integrity (absence of tarnish); (5) crystal habit elegance (parallel, radiating, or bladed); (6) matrix contrast and aesthetic balance; (7) condition and absence of re-attached crystals. Verified locality documentation and absence of cleaning residue act as strong multipliers across the above.

Naming history

The name Bornite has a specific etymological and historical context — see Mindat's reference entry for provenance details. We have retained naming data at the record level; published prose is paraphrased from factual fields rather than copied from source.