Calcite vs Corundum
| Property | Calcite | Corundum |
|---|---|---|
| Formula | CaCO3 | Al2O3 |
| Crystal System | Trigonal | Trigonal |
| Mineral Class | 05 Carbonates and Nitrates | 04 Oxides and Hydroxides |
| Mohs Hardness | 3.0 | 9.0 |
| Color | Colorless, white, yellow, orange, blue, green | Red (ruby), blue (sapphire), various colors |
| Luster | Vitreous | Adamantine |
| Streak | White | Colorless |
| Transparency | Transparent | Transparent |
| Cleavage | Perfect rhombohedral {1011} | None |
| Fracture | Conchoidal | Conchoidal to uneven |