Understanding Your Diamond






As creator of the Diamond 4Cs and the International Diamond Grading System™, GIA is not only a global authority, but the world’s trusted source for unbiased assessment.


A Diamond’s Cut Unleashes Its Light






  • Brightness: Internal and external white light reflected from a diamond






Diamond Color Actually Means Lack of Color






Before GIA universalized the D-to-Z Color Grading Scale, a variety of other systems were used loosely, from A, B, and C (used without clear definition), to Arabic (0, 1, 2, 3) and Roman (I, II, III) numbers, to descriptive terms like “gem blue” or “blue white,” which are notorious for misinterpretation. So the creators of the GIA Color Scale wanted to start fresh, without any association with earlier systems. Thus the GIA scale starts at the letter D. Very few people still cling to other grading systems, and no other system has the clarity and universal acceptance of the GIA scale.


No. Naturally colored diamonds outside the normal color range are called fancy-color diamonds. The FTC provides no guidelines for the use of the term “fancy-color” in the US, but there is general agreement in the international trade that fancy-color diamonds are either yellow or brown diamonds that have more color than a Z masterstone or they exhibit a color other than yellow or brown.


Diamond Carat Weight Measures a Diamond’s Apparent Size

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Some weights are considered “magic sizes” – half carat, three-quarter carat, and carat. Visually, there’s little difference between a 0.99 carat diamond and one that weighs a full carat. But the price differences between the two can be significant.


Diamond Clarity Refers to the Absence of Inclusions and Blemishes





  • Internally Flawless (IF) No inclusions visible under 10x magnification



Like the color scale, GIA’s clarity grading system developed because jewelers were using terms that could be misinterpreted, “loupe clean” or “piqué.” Today, even if you buy a diamond somewhere else in the world, the jeweler will most likely use terms like VVS1 or SI2, even if his or her language is French or Japanese instead of English.


Small crystals can become trapped in a diamond when it’s forming. Sometimes as a crystal grows it can develop irregularities in its atomic structure.