The refractive index of Canadian material (as measured via sodium light, 589.3 nm) is as follows: α 1.522; β 1.672–1.673; γ 1.676–1.679; biaxial negative.
De Brechungsindex vu kanadesche Material, wéi iwwer Natrium Liicht, 589.3 nm, ass wéi folgend: α 1.522, β 1.672-1.673, γ 1.676-1.679, biaxial negativ.