Gadolinium Gallium Garnet Faceting Information

Gadolinium Gallium Garnet or GGG, is a crystalline material of the garnet group which may also find use in jewelry as a gemstone or a diamond stimulant.

Home Learning Center Jewelry and Lapidary Cutting Information for Specific GemstonesGadolinium Gallium Garnet Faceting Information

By Jeff R. Graham

Gadolinium Gallium Garnet (GGG) Color: Colorless, yellow, green, blue, pink, purple, red and orange
Moh's Hardness: 7
Refractive Index: 1.97 - 2.02
Critical Angle: 30.51°
Specific Gravity: 7.02
Cleavage: None
Fracture: Conchoidal
Dispersion: .045
Heat Sensitivity: Low
Birefringence (double refraction): None
Crystal Structure: Isometric

Treatments: None

What I prefer to polishing with: Tin lap with Alumina oxide. Zinc laps with 8,000 pre-polish and 50,000 polish.

Jeff's Comments: Cuts and polishes like Garnet. It is quite pretty especially in clear and light colors.

Design Links: 4-Way Stop - This is great for saturated rough if you have a piece that will work in the shape…
Princess - Nice in about any material
Brilliant Pear - Good in any color

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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