Gemstones with RI 1.490

4 gemstones have a refractive index range that includes 1.490. 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.

← All RI Values

GemstoneRI RangeSG RangeCrystal SystemOptic Character
Moldavite1.480 – 1.5102.32 – 2.38AmorphousSR
Obsidian1.480 – 1.5102.30 – 2.60AmorphousSR
Chrysocolla1.460 – 1.6302.00 – 2.40AmorphousAGG
Coral1.486 – 1.6582.60 – 2.70AggregateAGG
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