When we speak of a diamond’s clarity, we are referring to the presence of identifying characteristics on (blemishes) and within (inclusions) the stone.
If you think about the incredible amount of pressure it takes to create a diamond and the fact that natural diamonds are not grown in a sterile laboratory, it’s no surprise that most diamonds have flaws.
Basically there are two types of clarity characteristics: inclusions and blemishes. Inclusions refer to internal flaws and blemishes refer to surface defects. However, in the diamond grades listed below, you’ll note that none of the grades include the term “blemish” — for the purposes of grading diamonds, all flaws are called “inclusions.”
Inclusions include flaws such as feathers, knots and other minerals found in the diamond. Blemishes include scratches, pits, and chips. Some blemishes may also occur during the cutting processes (most often at the girdle).
Diamonds grades range from Flawless (diamonds which are completely free of blemishes and inclusions), to Included 3 (diamonds which possess large, heavy blemishes and inclusions that are visible to the naked eye). Diamond are graded for internal characteristics under 10 x loupe magnification and judged on the basis of five clarity factors: size, number, position, nature, colour and relief.
Flawless: No internal or external flaws. Extremely rare.
Internally flawless: no internal flaws, but some surface flaws. Very rare.
Very Very Slightly Included (two grades). Minute inclusions very difficult to detect under 10 x magnifications by a trained gemmologist.
Very Slightly Included (two grades). Minute inclusions seen only with difficulty under 10x magnification by a trained gemmologist
Slightly Included (two grades). Minute inclusions more easily detected under 10x magnification by a trained gemmologist
Included (three grades). Inclusions visible under 10x magnification AS WELL AS to the human eye.
Diamonds with higher clarity grades are more valued, with the exceedingly rare Flawless graded diamond fetching the highest price. While the presence of these clarity characteristics (inclusions and blemishes) does lower the clarity grade of a diamond, they can also be viewed as proof of a diamond’s identity. Minor inclusions or blemishes are useful because they help to identify certain diamonds. In addition, as synthetic diamond technology improves and distinguishing between natural and synthetic diamonds becomes more difficult, inclusions or blemishes can be used as proof of natural origin. GIA certificates include what is known as “plot” (map) of a diamond’s inclusions — think of it as a “diamond fingerprint.” Since no two diamonds are exactly the same, comparing the uniqueness of your diamond’s clarity characteristics with the plot provided on the diamond certificate offers assurance that the diamond you pay for is the same diamond you receive.
TIP: Diamonds with no or few inclusions and blemishes are more highly valued than those with less clarity because they are rarer.