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.

0

Gadolinium Gallium Garnet

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.

Never Stop Learning

When you join the IGS community, you get trusted diamond & gemstone information when you need it.

Become a Member

Get Gemology Insights

Get started with the International Gem Society’s free guide to gemstone identification. Join our weekly newsletter & get a free copy of the Gem ID Checklist!