IGS Background

Spinel Faceting Information


Helpful information such as successful tips and details on how to Spinel Facet gemstones. Essential information and guides necessary for Spinel faceting.

By Jeff R. Graham, updated on

Spinel cut in my Signature #6/spinel facet

Color: Red, purple, blue, lavender, green, pink, yellow (unusual), orange/peach
Moh's Hardness: 8
Refractive Index: 1.712-1.736
Critical Angle: 35.79°
Specific Gravity: 3.58-3.61
Cleavage: Imperfect
Fracture: Conchoidal, uneven
Dispersion: .02
Heat Sensitivity: None
Birefringence (double refraction): None
Crystal Structure: Isometric

Treatments: Generally none

What I prefer to polishing with: Alumina oxide on a Tin lap, Spectra Ultralap, 8,000 diamond pre-polish 50,000 diamond polish on a Zinc laps

Jeff's Comments: Spinels are easy to cut and come in about any color. Some rough has a grey under tone and I recommend against buying this type of rough. There are a few rare color change Spinels, but they are not common.

Design Notes: About any Spinel design will work well. As the rough gets more saturated I prefer checker board designs. For light rough I like deep brilliant designs.

Design Links: Cornered -This will work nicely in darker rough

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!