How to Determine the Clarity and Color of Diamonds

Diamond Clarity Scale

Diamond clarity is graded using letter grades, which indicate how many visible flaws (inclusions) can be detected in a stone when viewed under 10x magnification.

The most common grading scale is that introduced by the GIA (Gemological Institute of America) and consists of the following grades (from highest to lowest clarity):

• FL (Flawless)
• IF (Internally Flawless)
• VVS (Very Very Slightly Included; consists of sub-grades VVS1 and VVS2)
• VS (Very Slightly Included; has sub-grades VS1 and VS2)
• SI (Slightly Included; includes sub-grades SI1 and SI2)
• I (Included; consists of sub-grades I1, I2, and I3)

Determining Diamond Clarity

Assigning a clarity grade to a diamond is done by trained gemologists, who examine the stone under a microscope.

Unless you are a professional jeweler and are using grading equipment, it is very hard to assign an exact clarity grade to a diamond.

However, you could guess the approximate grade of a stone by looking at it with a 10x loupe. Here are some guidelines to help you determine what clarity a diamond has:

If you cannot see any flaws (lines, black spots, or blemishes) inside the stone when looking at it under 10x magnification, then the diamond most likely falls into the FL/IF/VVS1/VVS2 clarity range.

If a diamond doesn’t have visible flaws but you can see some inclusions when looking at it with a jeweler’s loupe or microscope, then the stone has a clarity grade that is probably VS1, VS2 or SI1.

Some of these stones may occasionally have flaws visible with the naked eye, but such inclusions will nevertheless be hard to detect.

Some diamonds have inclusions that are visible to the unaided eye but that are relatively small and/or located towards the edges of the stone.

Such diamonds are likely to be classified as SI2 – they are not clean enough to be considered SI1, but they are also not as visibly included as the stones in the I-clarity range.

Finally, stones that have flaws that are relatively big and easily visible to the naked eye would most likely be classified as I1/I2/I3-clarity diamonds.

It should be stressed that it is very hard to determine the exact clarity grade of a diamond just by looking at it unless you are a trained gemologist. For example, there are SI2 diamonds that have so many inclusions that you would think they should really be graded I1; there are VVS1 diamonds that you would say don’t deserve their high grade. Very subtle elements can make a difference when it comes to grade classification.

Diamond Color Scale

Color in diamonds is graded depending on whether a stone has yellow hues and how visible they are.

The GIA classifies diamond color in color groups, which contain individual color grades.

Here are the color groups according to this scale:

• Colorless (grades D, E, and F)
• Near Colorless (G, H, I, J)
• Faint Yellow (K, L, M)
• Very Light Yellow (N, O, P, Q, R)
• Light Yellow (from grade S down to Z)

While the name of the group a stone’s color belongs to can give you some idea of how tinted the diamond is, its exact color grade represents a much finer distinction.

How Diamond Color Grading Is Done

Professionals grade diamonds by using a set of so-called “master stones.” A master stone is a diamond that has already been determined to belong to a certain grade.

Diamond graders compare the diamond they are evaluating with a master stone of each grade until they find the one whose color is closest to that of the graded stone.

For the grading to be as accurate as possible, a diamond should be graded loose, in well-lit conditions.

Determining Diamond Color

It would be very hard to determine the exact color of a diamond unless you have a set of benchmark stones for each color grade (master stones) to compare the diamond being graded with.

One option is to go to a jewelry store and ask if the jeweler there can help you determine the color of your diamond by comparing it with master stones or other graded diamonds the store has in stock.

However, not all jewelers have diamonds of each single color grade, and if that’s the case, a color assessment may yield only approximate results.

You can try to estimate the color grade of the stone yourself. In such a case, to get a good view of your diamond, it is best to take it out of the mounting and place the stone under a lamp whose light has the characteristics of daylight. Depending on what the setting is made of, the reflections from its metal could alter the perceived color of the stone.

(Do not take the stone out of the mounting if you are not experienced in such a manipulation – you wouldn’t want to chip your stone or damage its setting.)

You are unlikely to be able to pinpoint the exact grade of the stone just by looking at it, but you might at least be able to determine to which color group it belongs.

Here’s how you can at least guess in which color group a stone is likely to fall:

Colorless/Near Colorless: If you cannot see any traces of yellowish tints when you inspect the diamond, then its color grade is likely in the D-E-F range.

Near Colorless stones graded G or H also do not appear to have visible color, and unless you have a Colorless stone to compare them with, you might not be able to determine whether a diamond is a D-E-F or G-H stone.

Near Colorless (lower end of the range): Near Colorless diamonds graded I or J look fairly white to the naked eye, but on close inspection, you might see some very faint color that is almost imperceptible.

Faint Yellow: If the diamond you are looking at seems reasonably white but has a very faint yellow tint that is nonetheless identifiable, then you may be dealing with a K, L or M stone. The diamond could also be J or I color.

Very Light Yellow: Stones in the N-O-P-Q-R range have a visible yellow tint, and although the hue is not intense at all, it is evident enough so that the diamond cannot be mistaken for a colorless or nearly colorless stone.

Light Yellow: If the diamond has a clearly visible yellow color, and it is moderate to strong, then it most likely falls into the S-Z range.

Note: These guidelines are for round diamonds. The cut of these stones enhances their brilliance, which makes any tints less noticeable. All else being equal, diamonds of most other cuts will look less colorless than a round stone of the same color grade.

In sum, it is very hard to pinpoint the exact clarity or color grade of a diamond, and even if you follow the above guidelines, your assessment is likely to be off.

The best way to determine the characteristics of a diamond is to have it graded by a professional or look at the stone’s grading report, if it has one.

The best grading option: You can always send the stone to the GIA or another reputable lab to have your diamond graded. This option will provide you with the most accurate evaluation, and you will also get an official report certifying your stone’s color grade and other quality characteristics.