Most diamonds have some inclusions or blemishes, which are typically microscopic markings within a diamond or on its surface — and which affect a diamond’s “clarity” and value.
No two diamonds are exactly alike, and this has to do with their clarity. The grade of clarity a diamond has depends on if it has any inclusions or blemishes, which are common. Put simply, the higher the clarity of a diamond, the fewer inclusions or blemishes. So-called “flawless” diamonds, or those with no inclusions or blemishes, are the most highly desirable — and the most expensive.
Think of an inclusion or blemish as a marking on the diamond perceived by the eyes (with magnification!) as a discoloration or mark. If the marking is within the diamond itself, it’s called an inclusion. If the marking is on the surface of the diamond, it’s called a blemish.
What causes inclusions and blemishes? They can occur while a diamond is forming — minerals can be trapped inside the stone — or when the diamond is cut, polished or set in a piece of jewelry.
When an expert looks at a diamond, he or she uses a gemological hand loupe and microscope to determine the diamond’s clarity. The jewelers’ loupe, a small 10-power (10x) magnifying glass, is typically the tool used to show a customer the characteristics of a diamond and is the standard magnification when assessing diamond clarity.
Most diamonds do have inclusions or blemishes, many of them too small to see with the naked eye. Your decision to purchase a diamond should also take into consideration its cut and color, as well as what is the right setting to display the diamond to its best advantage.
Five factors affecting the clarity grade
- Size of inclusions
- Number of inclusions
- Locations of inclusions (An inclusion located in the center of the diamond will affect the grade more than one in a facet.)
- Nature or type of inclusion (If the inclusion might affect a diamond’s durability, its value will be downgraded.)
- Relief, the color and depth/placement of inclusions