#DiamondTalk - A Little History the Gemological Institute of America's 4C's

Lab photo from the GIA Website  photo credit: Robert Weldon

If you are ready to pop the question and are in the market for a diamond, or you are a jeweler working on your next award winning collection it is critical that you know the factors that determine diamond value.

To eliminate the guesswork from grading a diamond’s color, graders compare it to
 masterstones that represent known colors in the GIA D-to-Z scale. -
© GIA & Tino Hammid

Until 1953 when the Gemological Institute of America introduced their 4c's standards, there was no agreed-upon standard by which diamonds could be judged. Colorless diamonds are scarce—most diamonds have tints of yellow or brown. So a colorless diamond could show up on the market as a AAA Diamond...but then again so could a faint yellow. It was the Wild West with the consumer usually coming out on the short end.

GIA proposed the first, and now globally accepted standard for describing diamonds: a D-to-Z color scale and Flawless-to-I3 clarity scale for diamonds.  This has become internationally recognized as the standard for evaluating diamond quality,looking at the 4C's - Color, Clarity, Cut, and Carat Weight. 

Fancy-shape diamonds, along with the classic round diamonds, are popular choices
for today’s jewelry consumer. Courtesy Lazare Kaplan Diamonds

The creation of the Diamond 4Cs was very important to diamond dealers, jewelers, and the consumer -- it meant there was now a language to communicate your needs that enabled a dealer to know exactly what you want.

A quick look at the 4C's:

Color - Diamonds that range from colorless to light yellow and brown fall within the normal color range. Within that range, colorless diamonds are the most rare, so they’re the most valuable. They set the standard for grading and pricing other diamonds in the normal color range.

Clarity - Like the rest of the 4Cs, clarity’s influence on value is directly related to the concept of rarity. Flawless is the top grade in the GIA Clarity Grading System. Diamonds graded Flawless don’t have visible inclusions or blemishes when examined under 10-power (10X) magnification by a skilled and experienced grader.

Cut - A diamond’s proportions determine how light performs when it enters the diamond. If light enters through the crown and goes out through the pavilion, the diamond will look dark and unattractive. Diamonds with different proportions and good polish make better use of the light, and will be bright, colorful, and scintillating.

Carat Weight - What often surprises people when they start learning about diamonds and carat weight isis the precision with which diamonds are weighed. Diamond weights are stated in metric carats, abbreviated “ct.” One metric carat is two-tenths (0.2) of a gram—just over seven thousandths (0.007) of an ounce. 

Large diamonds are more rare than small diamonds. The more scarce something is, the more it is worth. So a larger stone doesn’t just cost more. It also costs more per carat. A 1-carat diamond weighs the same as four 0.25-carat diamonds. But even if all the other quality factors are equal, the larger diamond is worth much more than the sum of the four smaller diamonds.