Comparison Chart for Ramaura™ Cultured Ruby & Natural Ruby
| Ramaura™ Cultured Ruby | Natural Ruby | |
| Hardness | 9.0 | 9.0 |
| Specific Gravity | 3.96 - 4.0 | 3.96 - 4.0 |
| Mineral | Corundum | Corundum |
| Crystal System | Hexagonal | Hexagonal |
| Composition | Al2O3 + Cr+3 | Al2O3 + Cr+3 |
| Refractive Index | 1.760 - 1.770 | 1.760 - 1.770 |
| Birefringence | 0.008 | 0.008 |