Comparison · Minerals
Bornite vs Covellite
Bornite and Covellite are easy to confuse because both are minerals. Bornite is harder (Mohs 3–3.25) than Covellite (Mohs 1.5–2), so Bornite will scratch Covellite and not the other way round. A fingernail (Mohs 2.5) scratches it easily. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Bornite and Covellite
- Bornite is harder (Mohs 3–3.25) than Covellite (Mohs 1.5–2), so Bornite will scratch Covellite and not the other way round. A fingernail (Mohs 2.5) scratches it easily.
- Streak color differs: Bornite leaves a grayish black streak on unglazed porcelain, Covellite leaves lead-gray to black.
- Both look metallic, so compare color, tarnish and weight rather than shine.
- They overlap in red, blue, purple, and multicolored, but Bornite also comes in brown and orange and Covellite also comes in black.
- Well-formed crystals give it away: Bornite is Orthorhombic (pseudocubic), Covellite is Hexagonal.
Bornite vs Covellite properties
| Property | Bornite | Covellite |
|---|---|---|
| Type | Minerals | Minerals |
| Mohs hardness | 3–3.25 | 1.5–2 |
| Luster | Metallic | Metallic to submetallic/resinous |
| Streak | Grayish black | Lead-gray to black |
| Transparency | Opaque | Opaque |
| Specific gravity | 4.9–5.3 | 4.6–4.76 |
| Crystal system | Orthorhombic (pseudocubic) | Hexagonal |
| Common colors | Copper red to brownish bronze (fresh), Iridescent purple-blue tarnish (peacock ore) | Indigo blue, Blue-black, Iridescent purple/red tarnish |
| Rarity | common | common |
| Typical specimen value | $2–$150+ | $2–$150+ |
Which is more valuable?
Typical specimens of Bornite and Covellite trade in a similar range, around $20.
About Bornite
Bornite is a copper iron sulfide mineral with the formula Cu5FeS4, prized by mineral collectors for the flashy iridescent tarnish that earns it the nickname peacock ore. Freshly broken surfaces show a coppery, brownish-bronze metallic color that oxidizes within hours to purple, blue, and pink iridescence. It is an important, though secondary, copper ore mineral found in many sulfide deposits worldwide.
About Covellite
Covellite is copper sulfide, CuS, a hexagonal mineral instantly recognizable for its deep indigo-blue color and the flashing, rainbow-like iridescence that appears on its surface as it tarnishes. It forms as a secondary mineral in the supergene enrichment zones of copper sulfide deposits, where descending groundwater alters primary copper minerals. Despite its striking appearance, covellite is quite soft and delicate compared to most sulfide minerals collectors encounter.
Bornite vs Covellite FAQ
Is Bornite the same as Covellite?
No. Both are minerals, but they are distinct species with different hardness, streak or luster. Bornite is harder (Mohs 3–3.25) than Covellite (Mohs 1.5–2), so Bornite will scratch Covellite and not the other way round. A fingernail (Mohs 2.5) scratches it easily.
How can you tell Bornite from Covellite?
Bornite is harder (Mohs 3–3.25) than Covellite (Mohs 1.5–2), so Bornite will scratch Covellite and not the other way round. A fingernail (Mohs 2.5) scratches it easily. Streak color differs: Bornite leaves a grayish black streak on unglazed porcelain, Covellite leaves lead-gray to black. Both look metallic, so compare color, tarnish and weight rather than shine.
Which is harder, Bornite or Covellite?
Bornite is harder: Mohs 3–3.25 against Mohs 1.5–2 for Covellite.
Which is more valuable, Bornite or Covellite?
Typical specimens of Bornite and Covellite trade in a similar range, around $20.
