Diamond vs Graphite
| Property | Diamond | Graphite |
|---|---|---|
| Formula | C | C |
| Crystal System | Cubic (Isometric) | — |
| Mineral Class | 01 Native Elements | — |
| Mohs Hardness | 10.0 | — |
| Color | Colorless, yellow, brown, blue, green, pink | — |
| Luster | Adamantine | — |
| Streak | None | — |
| Transparency | Transparent | — |
| Cleavage | Perfect octahedral {111} | — |
| Fracture | Conchoidal | — |
Key Differences
- ◆ Diamond (hardness 10) is the hardest natural mineral; graphite (hardness 1–2) is one of the softest — yet both are pure carbon.
- ◆ Diamond has a tetrahedral sp3 crystal structure; graphite has layered sp2 sheets held by weak van der Waals forces.
- ◆ Diamond is transparent with adamantine luster; graphite is opaque with metallic to dull luster.
- ◆ Diamond is an electrical insulator; graphite is a good electrical conductor.
- ◆ Diamond forms under extreme pressure in the mantle; graphite forms at low pressure in metamorphic rocks.