GIA assigns 5 “cut” grades to finished round brilliant cut diamonds, which are: Excellent, Very Good, Good, Fair and Poor.
Only “round – brilliant cut diamonds” receive a “Cut” grade from GIA, due to their symmetry and specific cut ratio formula, to unlock the most amount of fire and light dispersion. All other “fancy shapes” receive “polish” and “symmetry” grades from GIA but not “Cut” grades, due to their unique shapes and varying degrees of personal attributes in the eye of the beholder.
Diamonds also have various shapes, please see below to learn more about this.
The shape of a diamond has a lot of influence over the feel of their piece, and for the best aesthetic, the lines of the diamond should reflect the design. Here are a few of the most common diamond shapes that compliment the cut of the diamond.
Diamonds are available naturally in a variety of colors, including yellow, brown and rare pink and blue. Each GIA certified diamond is graded and assigned a letter, which identifies its color. The scale ranges from letters D to Z, signifying “colorless” to light yellow and brown.
Eleven clarity grades make up the GIA clarity scale, ranging from Flawless to I3. While flawless diamonds are extremely rare, the majority of diamonds have varying degrees of natural inclusions and blemishes. These characteristics also help identify each individual stone.
DIAMOND CARAT WEIGHT
Diamond weights are expressed in metric measurements called carats (ct.) and are expressed as decimal numbers, such as 1.00 ct, 5.23 ct and 10.45 ct.