Bornite
| Colour | Purple, Blue, Brown |
|---|---|
| Mohs hardness | 3–3.25 |
| Lustre | Metallic if fresh, iridescent tarnish |
| Streak | Grayish black |
| Crystal system | Orthorhombic |
| Transparency | Opaque |
| Cleavage | Poor on [111] |
| Fracture | Uneven to subconchoidal |
| Chemical formula | Cu 5 FeS 4 |
| Specific gravity | 5.06–5.08 |
What is Bornite?
Bornite, also known as peacock ore, is a sulfide mineral with chemical composition Cu5FeS4 that crystallizes in the orthorhombic system (pseudo-cubic). It is an important copper ore.
How to identify Bornite
- Lustre: Metallic if fresh, iridescent tarnish.
- Hardness: Mohs 3–3.25 — soft; a knife will scratch it.
- Streak: Grayish black.
- Habit: Orthorhombic crystal system.
Bornite in different forms
Stones often confused with Bornite
Frequently asked questions
How hard is Bornite?
Bornite is Mohs 3–3.25 on the hardness scale.
What colour is Bornite?
Bornite is typically purple, blue, brown (Copper red, bronze brown, purple).