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. You’ll learn about different kinds of clarity characteristics in Assignment 2.

Clarity characteristics might have negative influences on diamond’s value, but they have positive effects as well:

• The very different inclusions found in natural diamonds, lab-grown diamonds, and diamond imitations help gemologists separate them from each other.
• 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. A fashioned diamond can sometimes be recut or repolished to remove or reduce grade-setting characteristics, possibly resulting in a higher clarity grade. Whether or not a diamond’s clarity can be improved depends on the depth of the grade-setting characteristics, the presence of other characteristics, and the weight of the diamond. Removing too much weight can lower a diamond’s value, even while improving its clarity.

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 experienced 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.