YAG Yttrium aluminum garnet (yttrium aluminate)
Color: Wide range of colors available.
Moh’s hardness: 8.5
Refractive index: 1.833
Critical angle: 33°
Specific gravity: 4.55
Dispersion: Moderately high (.028)
Heat sensitivity: Low
Birefringence (double refraction): None
Crystal structure: Isometric
Treatments: YAG is a synthetic stone.
Cutting: Cuts similar to natural garnet.
Polishing: Alumina or diamond (50,000 or 100,000) on common polishing laps.