3.60-ct spinel - spinel buying guide3.60-ct spinel - spinel buying guide

Spinel Buying Guide

Our spinel buying guide can help you learn how spinels are graded, what to avoid, and how to identify a high-quality stone or a bargain in the rough.

6 Minute Read

Spinel Buying and the Four Cs

Although red and blue colored spinels command the highest prices, clarity and carat weight can also have a significant effect on value. Myanmar (“Burmese”) provenance always adds value.

The IGS spinel value listing has price guidelines for spinel buying with different color grades, sizes, and cut styles.


In the GIA color grading system, color consists of three qualities: hue, tone, and saturation. The basic hues are red, orange, yellow, green, blue, violet, and purple. Tone refers to a color’s relative lightness, from colorless (0) to black (10). Saturation refers to a color’s intensity, from grayish or brownish (1) to vivid (6). The dominant hue is capitalized. Other hues present are not capitalized and may be further described as “sl” for slightly and “st” for strongly.

Be aware when spinel buying that saturation or “spectral purity” is the color quality that will have the greatest impact on price. You could easily expect to pay five, ten or even twenty times as much per carat for the true red stone below on the right as for the less saturated pink one on the left.

Red Spinels

Top color for so-called “ruby spinels” consists of…

International Gem Society

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!