Shape

Type of cut

Length (mm)

Width (mm)

Weight (cts)

Price/ct (US$)

Price (US$)

Preços apresentados são para exportação e não contemplam impostos e frete. Para aquisição no mercado nacional, impostos e frete serão acrescidos e apresentados no checkout antes da conclusão da compra.

Showing all 2 results

Indicolite

Generic Information:

Name Origin: Stone belonging to the Tourmaline Group. It gets its name from “Indigo” which means dark blue.

Main Colors: Intense color from violet-blue to slightly grayish to greenish-blue.

Producing Countries: Indicolite deposits are found in pegmatites and alluvial deposits. The most important supplier is the state of Minas Gerais, Brazil. There are deposits in Namibia, Madagascar, Mozambique, and Nigeria among others.

Common Shapes: As it is a gem that is always intense in color, Indicolite is usually cut in a rectangular, octogonal or antique shape, and always with the sides quite vertical.

Usual Treatment: Heat treatment between 500 to 700°C is used to lighten the original very intense blue a little.

Gemological Data:

Species:Blue or indicolite tourmaline
Hardness of Mohs:7/7,5
Specific Density:3,06 (+0,15 / -0,05)
Cleavage:None.
Fracture:Uneven, brittle conical
Crystal System:Hexagonal (trigonal) crystals usually elongated with triangular section and rounded faces, clear striations parallel to the main axis; often, several prisms grow together.
Chemical Composition:(NaLiCa) (Fe₁₁MgMnAl) ₃Al₆ [(OH) ₄ (BO₃) ₃Si₆O₁₈)] Complex aluminum borosilicate of variable composition.
Transparency:Transparent to opaque
Refractive Index:1,624-1,644
Birefringence:0.020
Dispersion:0,017
Pleochroism:Dark-blue and greenish-blue.
Luster:Vitreous
Fluorescence:Weak or none