Many of these color distinctions are so subtle that they are invisible to the untrained eye; however, these distinctions make a very big difference in diamond quality and price.
WHY DOES THE GIA COLOR GRADING SYSTEM START AT D?
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.
ARE DIAMONDS GRADED AS Zs CONSIDERED FANCY-COLOR?
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 Clarity
Natural diamonds are the result of carbon exposed to tremendous heat and pressure deep in the earth. This process can result in a variety of internal characteristics called ‘inclusions’ and external characteristics called ‘blemishes.’
Evaluating diamond clarity involves determining the number, size, relief, nature, and position of these characteristics, as well as how these affect the overall appearance of the stone. While no diamond is perfectly pure, the closer it comes, the higher its value.
The GIA Diamond Clarity Scale has 6 categories, some of which are divided, for a total of 11 specific grades.
- Flawless (FL) No inclusions and no blemishes visible under 10x magnification
- Internally Flawless (IF) No inclusions visible under 10x magnification
- Very, Very Slightly Included (VVS1 and VVS2) Inclusions so slight they are difficult for a skilled grader to see under 10x magnification
- Very Slightly Included (VS1 and VS2) Inclusions are observed with effort under 10x magnification, but can be characterized as minor
- Slightly Included (SI1 and SI2) Inclusions are noticeable under 10x magnification
- Included (I1, I2, and I3) Inclusions are obvious under 10x magnification which may affect transparency and brilliance
Many inclusions and blemishes are too tiny to be seen by anyone other than a trained diamond grader. To the naked eye, a VS1 and an SI2 diamond may look exactly the same, but these diamonds are quite different in terms of overall quality. This is why expert and accurate assessment of diamond clarity is extremely important.