Spessartite (Garnet)

Spessartite Garnets

Color: Orange to red brown
Moh’s Hardness: 7-7.5
Refractive Index: 1.79-1.81
Critical Angle: 33.96°
Specific Gravity: 4.12-4.20
Cleavage: Imperfect
Fracture: Subconchoidal
Heat Sensitivity: Slightly
Birefringence (double refraction): 0.027
Crystal Structure: Isometric, rhombic, dodecahedron,icositetrahedron

Treatments: Generally none

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

Jeff’s Comments: Most Garnets cut and polish pretty easily (with the exception of a piece with bubbles/flaws) and are 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: Most of the orange/brown/red types of Garnet are saturated and I prefer checker boards and bar cut in them. On lighter Grossular Garnets and Mail types of Garnets I prefer a deeper design.

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