Corundum
| Name | Corundum |
| Chemical Formula | Al2O3 |
| Mohs Hardness | 9 |
| Density | 3.98 - 4.1 |
| Streak | White |
| Luster | Adamantine, Vitreous or Pearly |
| Refractive Index | 1.76 - 1.77 |
| Color | Colorless, blue, red, pink, yellow, grey, golden-brown |
| Gem Types | Sapphire Ruby |
| Name | Corundum |
| Chemical Formula | Al2O3 |
| Mohs Hardness | 9 |
| Density | 3.98 - 4.1 |
| Streak | White |
| Luster | Adamantine, Vitreous or Pearly |
| Refractive Index | 1.76 - 1.77 |
| Color | Colorless, blue, red, pink, yellow, grey, golden-brown |
| Gem Types | Sapphire Ruby |
