Gemstones with SG 2.15
6 gemstones have a specific gravity range that includes 2.15. Specific gravity measures density relative to water — a key diagnostic property for gem identification. Measured by hydrostatic weighing or heavy liquids.
| Gemstone | SG Range | RI Range | Crystal System | Hardness |
|---|---|---|---|---|
| Black Opal | 2.09 – 2.16 | 1.440 – 1.460 | Amorphous | 5.5–6.5 |
| Opal | 1.98 – 2.25 | 1.370 – 1.470 | Amorphous | 5.5–6.5 |
| Chrysocolla | 2.00 – 2.40 | 1.460 – 1.630 | Amorphous | 2.5–7 |
| Fire Opal | 1.98 – 2.20 | 1.370 – 1.470 | Amorphous | 5.5–6.5 |
| Hackmanite | 2.14 – 2.40 | 1.483 – 1.487 | Cubic | 5.5–6 |
| Sodalite | 2.14 – 2.40 | 1.483 – 1.487 | Cubic | 5.5–6 |