round brilliant-cut diamondround brilliant-cut diamond

Traditional Diamond Cut Grading Methods


Traditional diamond cut grading methods prepare gemologists for making evaluations with minimal time, tools, and references. This step-by-step guide covers the traditional GIA and AGS systems.

30 Minute Read

Why Learn Traditional Diamond Cut Grading Methods?

In 2005, the Gemological Institute of America (GIA) released a new, modern method for evaluating diamond cuts. However, beginning gemologists should learn traditional diamond cut grading for two reasons.

  • You’ll likely come across grading reports that utilize older methods. They’ve been used on thousands of reports that will be around for many years to come.
  • Learning traditional diamond cut grading will show you how to evaluate cuts by eye. When you examine diamonds away from your shop, you’ll need something to fall back on.

The Ideal Cut (May Not be Ideal)

round brilliantThe essential problem of evaluating the cut revolves around determining the ideal cut for a diamond. Today, most experts agree, within a small range, on what an ideal cut is. The closer a cut diamond comes to these ideal proportions, the higher its value per carat. However, among diamond cutters and the public alike, no widespread demand exists for ideal-cut diamonds. Beauty comes first and, indeed, it does lie in the eyes of the beholder, not necessarily in ideal proportions.

When cutting and buying diamonds, cutters and customers must find a compromise between beauty and size. Cutting most diamond crystals requires either…


Donald Clark, CSM IMG

The late Donald Clark, CSM founded the International Gem Society in 1998. Donald started in the gem and jewelry industry in 1976. He received his formal gemology training from the Gemological Institute of America (GIA) and the American Society of Gemcutters (ASG). The letters “CSM” after his name stood for Certified Supreme Master Gemcutter, a designation of Wykoff’s ASG which has often been referred to as the doctorate of gem cutting. The American Society of Gemcutters only had 54 people reach this level. Along with dozens of articles for leading trade magazines, Donald authored the book “Modern Faceting, the Easy Way.”

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!