Gemstones with RI 1.610
11 gemstones have a refractive index range that includes 1.610. 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 |
|---|---|---|---|---|
| Sugilite | 1.607 – 1.610 | 2.74 – 2.80 | Hexagonal | DR_U- |
| Grandidierite | 1.590 – 1.623 | 2.85 – 2.98 | Orthorhombic | DR_B- |
| Nephrite | 1.600 – 1.627 | 2.90 – 3.03 | Aggregate | AGG |
| Pearl | 1.520 – 1.690 | 2.60 – 2.85 | Aggregate | AGG |
| Larimar | 1.595 – 1.640 | 2.74 – 2.90 | Triclinic | DR_B+ |
| Topaz | 1.609 – 1.643 | 3.49 – 3.57 | Orthorhombic | DR_B+ |
| Turquoise | 1.610 – 1.650 | 2.60 – 2.90 | Triclinic | AGG |
| Lapis Lazuli | 1.500 – 1.670 | 2.70 – 2.90 | Aggregate | AGG |
| Coral | 1.486 – 1.658 | 2.60 – 2.70 | Aggregate | AGG |
| Chrysocolla | 1.460 – 1.630 | 2.00 – 2.40 | Amorphous | AGG |
| Rhodochrosite | 1.600 – 1.820 | 3.40 – 3.70 | Trigonal | DR_U- |