Indicolite Tourmaline Faceting Information

Practical tips on Indicolite Tourmaline Faceting. Covers Indicolite Tourmaline Facet / Faceting Information related issues, news, research, tips, and guide.

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Atlas cut in blue Tourmaline/indicolite tourmaline
Altas-cut indicolite tourmaline by Jeff Graham.

Color: Blue, sometimes with a hint of green
Moh's Hardness: 7-7.5
Refractive Index: 1.616-1.652
Critical Angle: 38.23°
Specific Gravity: 3.02-3.26
Cleavage: None
Fracture: Uneven, small conchoidal.
Dispersion: .017
Heat Sensitivity: Can be delicate and care must be taken when dopping with heat and wax.
Dichroic: Strong (many color variations)
Birefringence (double refraction): Medium (.014-.024)
Crystal structure: Hexagonal

Treatments: Generally not treated, but sometimes heated to lighten dark rough.

What I prefer to polishing with: Alumina oxide with a tin lap (scored).

Jeff's Comments: Cuts and polishes like any other Tourmaline. Can be problematic, some rough seems to be under stress and it is not unusual to have fractures show up during cutting. Some rough from certain locations is very brittle (maybe from heating, there is no way to be sure). Orientation is important, go for the best color, "c" axis is often closed or dark.

Design Notes: About any Tourmaline design will work well for an indicolite tourmaline, although I generally prefer a shallow checkerboard on darker rough. My Smith Bar is a very good choice for dark axis "c" rough. Also most of my reflector designs work very well.

Design Links: Signature #4 - This is good for about any rough
Easy Emerald - This is a classic and works well on poor "c" axis colored stones
Smith Bar - This is a classic and works well on poor "c" axis colored stones

Jeff R. Graham

The late Jeff Graham was a prolific faceter, creator of many original faceting designs, and the author of several highly-regarded instructional faceting books such as Gram Faceting Designs.

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