Gemstones with RI 1.760
9 gemstones have a refractive index range that includes 1.760. Refractive index measures how much light bends when entering a gem — it's one of the most diagnostic properties for identification. Measured with a gemological refractometer.
| Gemstone | RI Range | SG Range | Crystal System | Optic Character |
|---|---|---|---|---|
| Malaya / Umbalite Garnet | 1.730 – 1.780 | 3.65 – 3.87 | Cubic | SR |
| Rhodolite Garnet | 1.740 – 1.770 | 3.74 – 3.94 | Cubic | SR |
| Color-Change Garnet | 1.740 – 1.765 | 3.65 – 3.80 | Cubic | SR |
| Hessonite Garnet | 1.730 – 1.760 | 3.59 – 3.65 | Cubic | SR |
| Pyrope Garnet | 1.730 – 1.760 | 3.62 – 3.87 | Cubic | SR |
| Tsavorite Garnet | 1.730 – 1.760 | 3.59 – 3.65 | Cubic | SR |
| Benitoite | 1.757 – 1.804 | 3.64 – 3.68 | Hexagonal | DR_U+ |
| Malachite | 1.655 – 1.909 | 3.60 – 4.05 | Monoclinic | DR_B- |
| Rhodochrosite | 1.600 – 1.820 | 3.40 – 3.70 | Trigonal | DR_U- |