Gemstones with SG 3.10
8 gemstones have a specific gravity range that includes 3.10. 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 |
|---|---|---|---|---|
| Chrome Tourmaline | 3.00 – 3.20 | 1.624 – 1.660 | Trigonal | 7–7.5 |
| Tourmaline | 3.01 – 3.26 | 1.624 – 1.644 | Trigonal | 7–7.5 |
| Indicolite | 3.02 – 3.10 | 1.624 – 1.644 | Trigonal | 7–7.5 |
| Paraiba Tourmaline | 3.02 – 3.10 | 1.624 – 1.644 | Trigonal | 7–7.5 |
| Rubellite | 3.02 – 3.10 | 1.624 – 1.644 | Trigonal | 7–7.5 |
| Green Tourmaline | 3.00 – 3.10 | 1.616 – 1.650 | Trigonal | 7–7.5 |
| Watermelon Tourmaline | 3.00 – 3.10 | 1.616 – 1.650 | Trigonal | 7–7.5 |
| Thulite | 3.10 – 3.38 | 1.691 – 1.704 | Orthorhombic | 6–7 |