Limits RegistryPUBLIC RECORD
Limits RegistryRutile (titanium dioxide) has one of the highest refractive indices of any naturally occurring transparent mineral, at approximately 2.6-2.9 depending on crystal orientation (it is birefringent) — higher even than diamond's 2.42 — giving cut rutile gemstones an intense fire and brilliance, though rutile's softness limits its use mainly to specialty and synthetic-substitute jewelry rather than diamond's practical hardness advantage.
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Rutile (titanium dioxide) has one of the highest refractive indices of any naturally occurring transparent mineral, at approximately 2.6-2.9 depending on crystal orientation (it is birefringent) — higher even than diamond's 2.42 — giving cut rutile gemstones an intense fire and brilliance, though rutile's softness limits its use mainly to specialty and synthetic-substitute jewelry rather than diamond's practical hardness advantage.
The highest refractive index confirmed for a naturally occurring, gem-quality transparent mineral, measured at standard visible-light sodium D-line wavelength.
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1 accepted Claim, with 1 linked evidence records.
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Limits Registry. LR-HIGHEST-REFRACTIVE-INDEX-NATURAL-MATERIAL. Highest refractive index of a naturally occurring transparent mineral. 2026.