Spinel

Refractive Index: 1.7152–1.7161
Abbe Number: 60.4–60.6
Crystal System: Isotropic (cubic)
Formation: Natural
Dispersion Data: Measured (published fit)
Fits: 2

Refraction Fits

Fit #1— Tropf 1991

Sellmeier

Valid 0.35–5.5 µm

$n$

n

= 1.7161

V_{D}

= 60.6

n^{2} = 1 + \frac{1.8938 λ ^{2}}{λ ^{2} - 0.009884} + \frac{3.0755 λ ^{2}}{λ ^{2} - 2.505 e + 2}

W.J. Tropf & M.E. Thomas, "Magnesium aluminum spinel (MgAl₂O₄)," in E.D. Palik (ed.), Handbook of Optical Constants of Solids II, Academic Press (1991), pp. 881–895

Fit #2— Specimen Cauchy fit

Shannon / Cauchy

$n$

n

= 1.7152

V_{D}

= 60.4

n^{2} = 1 + \frac{λ ^{2}}{0.5311 ( λ ^{2} - 0.010544 )}

Absorption Specimens

Myanmar, Mandalay Division, Mogok

Myanmar, Mandalay Division, Mogok

Myanmar, Mandalay Division, Mogok

Myanmar, Mandalay Division, Mogok

Myanmar, Mandalay Division, Mogok

Myanmar, Mandalay Division, Mogok

Myanmar, Mandalay Division, Mogok

Myanmar, Mandalay Division, Mogok

Myanmar, Mandalay Division, Mogok

Pakistan, Gilgit-Baltistan Region, Hunza Valley

Pakistan, Gilgit-Baltistan Region, Hunza Valley

Sri Lanka, Sabaragamuwa Province, Ratnapura

Sri Lanka, Sabaragamuwa Province, Ratnapura

Sri Lanka, Sabaragamuwa Province, Ratnapura

Tajikistan, Gorno-Badakhshan Province, Pamir Mountains