Gemstones with SG 1.40
1 gemstone have a specific gravity range that includes 1.40. 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 |
|---|---|---|---|---|
| Jet | 1.10 – 1.40 | 1.640 – 1.680 | Amorphous | 2.5–4 |