Gemstones with SG 2.90
6 gemstones have a specific gravity range that includes 2.90. 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 |
|---|---|---|---|---|
| Grandidierite | 2.85 – 2.98 | 1.590 – 1.623 | Orthorhombic | 7–7.5 |
| Prehnite | 2.82 – 2.94 | 1.611 – 1.665 | Orthorhombic | 6–6.5 |
| Nephrite | 2.90 – 3.03 | 1.600 – 1.627 | Aggregate | 6–6.5 |
| Larimar | 2.74 – 2.90 | 1.595 – 1.640 | Triclinic | 4.5–5 |
| Lapis Lazuli | 2.70 – 2.90 | 1.500 – 1.670 | Aggregate | 5–6 |
| Turquoise | 2.60 – 2.90 | 1.610 – 1.650 | Triclinic | 5–6 |