
Judging gemstone value is complex, and new gemologists can have trouble with this. These four exercises can help you learn to evaluate “bargain gems.”
6 Minute Read
Of course, these exercises have limits. You can’t always accurately judge gem colors through pictures on a computer monitor. Thus, when possible, I’ll give you image comparisons to work with. Also, values vary over time, so I’ll give you prices to use for each exercise. (Editor’s note: the IGS Gem Price Guide numbers and information Donald Clark quotes are based on 2016 values).
Be sure to review the following articles:
You’re looking for gems for your custom jewelry settings that will complement the quality and labor you’ve put into your settings. Of course, you want them at prices that will allow profit. While shopping at a local gem show, you find the following items: a tourmaline, a Thai ruby, an African ruby, and an emerald.
You come across this tourmaline with a distinctive personality. You don’t find this in most elongated, green tourmalines.
For some time, you’ve had a special design in mind for a long, thin, emerald-cut gem. This custom-cut, eye-clean stone weighs 4.6 carats. The asking price is…









When you join the IGS community, you get trusted diamond & gemstone information when you need it.

Of course, these exercises have limits. You can’t always accurately judge gem colors through pictures on a computer monitor. Thus, when possible, I’ll give you image comparisons to work with. Also, values vary over time, so I’ll give you prices to use for each exercise. (Editor’s note: the IGS Gem Price Guide numbers and information Donald Clark quotes are based on 2016 values).
Be sure to review the following articles:
You’re looking for gems for your custom jewelry settings that will complement the quality and labor you’ve put into your settings. Of course, you want them at prices that will allow profit. While shopping at a local gem show, you find the following items: a tourmaline, a Thai ruby, an African ruby, and an emerald.
You come across this tourmaline with a distinctive personality. You don’t find this in most elongated, green tourmalines.
For some time, you’ve had a special design in mind for a long, thin, emerald-cut gem. This custom-cut, eye-clean stone weighs 4.6 carats. The asking price is…

Judging gemstone value is complex, and new gemologists can have trouble with this. These four exercises can help you learn to evaluate “bargain gems.”

Please become a member to read this entire article and gain access to hundreds more like it. As a member, you'll also get...