IGS Background

Grossular Faceting Information


Faceting Information such as details, guides, tips and tricks. Choose which best fit the criteria for Grossular gemstones together with helpful details.

By Jeff R. Graham, updated on

Grossular Garnet

Color: Green yellow, copper, brown
Mohs 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

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!