Grossular Faceting / Facet Garnet Information


Grossular (Garnet)

Little Mo in Mali Garnet/grossular

Color: Green yellow, copper, brown
Moh’s Hardness: 7.5
Refractive Index: 1.73-1.75
Critical Angle: 35.31°
Specific Gravity: 3.60-3.68
Cleavage: Imperfect
Fracture: Subconchoidal
Heat Sensitivity: Moderate
Birefringence (double refraction): 0.027
Crystal Structure: Isometric, rhombic, dodecahedron, icositetrahedron

Tsavorite Garnet – Green – vanadium is the green colorant. It is usually only available in small sizes and care must be taken when cutting because it tends to cut dark stones. I usually cut checker boards and opposed bars in larger rough.

Treatments: Generally none

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

Jeff’s Comments: This is some of my personal favorite material to cut, Mail Garnets in particular. Most Garnets cut and polish pretty easily (with the exception of a piece with bubbles/flaws) and a re really not much of a problem. Pre-polish with a 1200 steel (not Nu Bond, it will leave orange peel) and polish with tin lap.

Design Notes: I prefer these in deep brilliant designs, the sparkle is diamond like.

Design Links:
Tic Tac – Good for dark material
Smith Bar – Great for any material
Brilliant Pear – Nice in about anything

About the author
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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