Tourmaline

Elbaite

Refractive Index: 1.6350
Abbe Number: 64.0
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

$n$

n

= 1.6350

V_{D}

= 64.0

n (λ) = 1.62 + 0.005194/ λ^{2}

Dispersion 0.017 from GIA tables; n_D taken as mean of ordinary (1.640) and extraordinary (1.620) rays for elbaite-typical tourmaline. No published Sellmeier.

Absorption Specimens

Afghanistan, Nuristan Province

Brazil, Minas Gerais State

Brazil, Minas Gerais State, Conselheiro Pena

Brazil, Minas Gerais State, Governador Valadares

Brazil, Minas Gerais State, Itambacuri

Brazil, Minas Gerais State, Itinga

Brazil, Minas Gerais State, Teofilo Otoni

Kenya, Coast Province (Taita-Taveta District), Voi

Kenya, Eastern Province, Embu

Madagascar, Antananarivo Province (Vakinankaratra District), Ambohimanambola (Anjanabonoina Mine)

Mozambique, Nampula Province, Nacala

Mozambique, Nampula Province, Nacala

Mozambique, Nampula Province, Nacala

Mozambique, Nampula Province, Nacala

Mozambique, Zambezia Province, Alto Ligonha

Mozambique, Zambezia Province, Alto Ligonha

Mozambique, Zambezia Province, Alto Ligonha

Namibia, Erongo Region (Karibib District), Karibib

Namibia, Erongo Region (Karibib District), Karibib (Neu Schwaben Mine)

Namibia, Erongo Region (Karibib District), Otjimbingwe (Otjimbingwe Mine)

Namibia, Erongo Region (Karibib District), Otjimbingwe (Otjimbingwe Mine)

Nepal, Eastern Region (Sagarmatha Zone), Solukhumbu District - Khumbu Valley

Nepal, Western Region (Gandaki Zone), Manang

Nepal, Western Region (Gandaki Zone), Manang

Sri Lanka, Sabaragamuwa Province, Ratnapura

United States, California (San Diego County), Pala (Stewart Lithia Mine)

Zambia, Eastern Province, Chipata