Few things in nature are absolutely perfect. That’s as true of diamonds as anything else. Diamonds have internal features, called inclusions, and surface irregularities, called blemishes. Together, they’re called clarity characteristics. Clarity is the relative absence of inclusions and blemishes.
Among other things, blemishes include scratches and nicks on a diamond’s surface. Inclusions are on the inside, or they might extend into the interior from the surface of the stone.
Clarity characteristics might have negative influences on diamond’s value, but they have positive effects as well:
• They help gemologists separate diamond from simulants. Inclusions in diamonds often have a different appearance from inclusions in simulants.
• Because no two diamonds have exactly the same clarity characteristics, they can help identify individual stones.
• They provide scientists with valuable information about how diamonds form.
Inclusions normally have more impact on a stone’s beauty and value than blemishes. That’s because many blemishes are relatively easy to remove. It’s possible to remove an inclusion that’s close to the surface, but that would cause a reduction in the diamond’s weight. Recutting or repolishing a diamond to remove a blemish, on the other hand, often increases its value. The impact of any weight loss is usually offset by the improved clarity.
Here’s an example: A cutter in New York removed some minor blemishes from a 1.02-ct. diamond with excellent color. The diamond lost a small amount of weight—after recutting, it weighed 1.01 cts.—but the removal of the blemishes improved the diamond’s clarity and increased its value by $1,100.
Like the rest of the Four Cs, 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 experi- enced grader.
Flawless diamonds are very rare—so rare, in fact, that it’s possible to spend a lifetime in the jewelry industry without ever seeing one. As you might imagine, they command top prices.
At the lower end of the scale are diamonds with inclusions that can easily be seen by the unaided eye. The stones that make up the bulk of the retail diamond market fall between the two extremes. They usually have inclusions that are visible only under magnification.
GIA Diamond Clarity Grading System:
Flawless diamonds show no inclusions or blemishes of any kind when examined under 10X magnification by a skilled grader. A diamond can have these characteristics and still qualify as Flawless:
• Extra facets not visible in the face-up view
• Naturals confined entirely to the girdle, as long as they don’t thicken the girdle or distort its outline
• Internal graining that’s not reflective, white, or colored, and that doesn’t significantly affect transparency
• Inscriptions that don’t appear to penetrate the surface when viewed at 10X
An IF diamond shows no inclusions when examined by an experienced grader using 10X magnification. It does, however, have some minor blemishes, such as surface grain lines, naturals, and extra facets. Except for surface grain lines, the blemishes can often be removed by having the diamond repolished. This increases an IF diamond’s clarity grade to Flawless, but it’s rarely done. Flawless and IF diamonds are extremely rare.
Very Very Slightly Included (VVS1 and VVS2)
VVS diamonds contain minute inclusions that are difficult even for experi- enced graders to see under 10X magnification. In VVS1, they are extremely difficult to see in the face-up view, or small and shallow enough to be removed by minor repolishing. In VVS2, they are very difficult to see. They might be pinpoints, tiny feathers, internal graining, a bearded girdle, or tiny
Very Slightly Included (VS1 and VS2)
VS diamonds contain small or minor inclusions observed with effort under 10X magnification. VS diamonds typically have small included crystals, small clouds, or small feathers.
Slightly Included (SI1 and SI2)
SI diamonds contain inclusions that are noticeable to an experienced grader under 10X magnification. Typically, these are clouds, included crystals, knots, cavities, and feathers.
I1 - I2
Included (I1, I2, and I3)
Diamonds that fall in the I range contain inclusions that are obvious under 10X magnification. They might contain large feathers or large included crystals. In some cases the inclusions affect transparency and brilliance.
There is certainly a market for I1 and I2 diamonds, and they’re carried in many retail stores. They’re especially attractive to the customer who wants the largest stone possible and is willing to compromise on clarity to get it. Diamonds in the I3 category are less popular: They often lack transparency and durability.