Apophyllite

Refractive Index: 1.5360
Abbe Number: 72.0
Crystal System: Isotropic (cubic)
Formation: Natural
Dispersion Data: Approximate (from n, V)
Fits: 1

Refraction Fits

Fit #1— Cauchy from (n_D, V_D)

Cauchy approximation

Valid 0.38–0.78 µm

$n$

n

= 1.5360

V_{D}

= 72.0

n (λ) = 1.5248 + 0.003897/ λ^{2}

Zeolite-like phyllosilicate. GIA dispersion 0.011. Source: GIA / Winchell / Liddicoat gemological tables.

Absorption Specimens

India, Maharashtra State (Poona District)