More clarity characteristics can mean a lower grade, but grades are normally set by how readily you can see the characteristics, not by counting them. For example, a diamond with a number of minute, pinpoints can still qualify as VVS. On the other hand a single large, dark, or centrally located included crystal could drop the grade into VS, SI, or even I Clarity.

Inclusions are most visible when they’re directly under the table. Inclusions under the crown facets or near the girdle are usually more difficult to see-that’s why you have to examine the stone from several angles to find all of its characteristics. The worst location for an inclusion is where it becomes a reflector. If it lies under the table and near the pavilion, the pavilion facets can act as mirrors and reflect multiple images of the inclusion. This can have a major effect on the grade if the reflections are visible in the face up position. The position of potentially damaging inclusions, such as feathers, large knots, and included crystals can also be significant. For example, a feather might get bigger. Normally, feathers won’t grow during ordinary wear, and the mounting protects those that reach the pavilion, but feathers that extend to the girdle or crown-the exposed parts of the stone-might grow if the diamond strikes something hard enough. A central location increases an inclusions impact on a diamond’s clarity grade. Inclusions located directly under the table affect the clarity grade of a diamond more than those located on the backside of the stone or under the facets.

The nature, or type, of a clarity characteristic tells you whether it’s an inclusion or a blemish and if it poses any risk to the stone. Most characteristics don’t. Generally, if a stone has durability problems, it doesn’t survive the friction and pressure of the cutting process. The effect of an inclusion on durability is determined by its size and location. For example, a large feather that reaches the crown poses a durability risk, but a small one probably doesn’t.

NOTE: if an inclusion has the potential to cause damage to a stone, it CAN affect the grade, but this is RARE, and usually applies only to included diamonds. According to GIA, the grader probably would NOT lower the grade of a stone on this basis alone.

Color or relief can affect the visibility of a characteristic as much as its size does. Generally, the more an inclusion differs in color from its host, the more obvious it is. Relief is the contrast between the inclusion and the stone. The greater the relief, the more it will affect the clarity grade. Although, most diamond inclusions are white or colorless, some are black, brown, dark red, or on the rare occasion, Green. Since colored inclusions are easier to see, they might lower the grade more than a colorless inclusion. A black pinpoint might be an exception-it’s often more difficult to see than a white one.