Benitoite

Refractive Index
1.7800
Abbe Number
30.0
Crystal System
Isotropic (cubic)
Formation
Natural
Dispersion Data
Approximate (from n, V)
Fits
1

Refraction Fits

Fit #1— Cauchy from (n_D, V_D) — isotropic approximation of uniaxial species

Cauchy approximation

Valid 0.38–0.78 µm

= 1.7800 = 30.0
n4004505005506006507007501.7601.7801.8001.8201.840

Dispersion 0.044 from GIA tables (comparable to diamond); n_D 1.78 as mean of ordinary (1.757) and extraordinary (1.804) rays. No published Sellmeier.

Absorption Specimens

LED
SUN
I
F
 
Benitoite
United States, California (San Benito County), New Idria District (Dallas Gem Mine)
LED
SUN
I
F
 
Benitoite
United States, California (San Benito County), New Idria District (Dallas Gem Mine)
LED
SUN
I
F
 
Benitoite
United States, California (San Benito County), New Idria District (Dallas Gem Mine)