Diamond Clarity Guide

Diamond clarity describes the presence and visibility of internal characteristics called inclusions and external characteristics called blemishes. Clarity is one of the 4Cs used to describe diamond quality, and it applies to both natural and laboratory-grown diamonds. Professional grading evaluates these characteristics under standardized conditions, generally using 10× magnification.

Diamond clarity scale

What determines a diamond clarity grade?

Clarity grading is not based only on the number of inclusions. Graders consider five major factors: size, number, position, nature, and relief. Relief refers to how strongly a characteristic contrasts with the surrounding diamond and therefore how easy it is to see.

This is why two diamonds with the same clarity grade can look different. A small inclusion near the edge may be less visually noticeable than a similar inclusion under the center of the table.

Inclusions vs. blemishes

Inclusions are internal features or features that extend into the diamond. Blemishes are surface characteristics. Both can influence the final grade depending on their size, visibility, location, and nature.

What does “eye-clean” mean?

“Eye-clean” is an informal term used when clarity characteristics are not readily visible to the unaided eye under normal viewing conditions. It is not an official laboratory grade. A diamond can contain inclusions visible at 10× magnification while still appearing clean in everyday wear.

How diamond shape affects clarity

Facet style can change how easy inclusions are to notice. Brilliant-style cuts use many small facets and reflections that can help disguise minor characteristics. Step cuts such as emerald and Asscher have broader, more open facets, so inclusions may be easier to see.

How diamond size affects clarity visibility

As diamonds become larger, individual facets and internal areas can also become easier to inspect. A clarity grade that appears visually clean in a smaller diamond may look different in a larger stone depending on the location and type of inclusion.

Clarity and laboratory-grown diamonds

Laboratory-grown diamonds are real diamonds and are graded for clarity using the same core grading framework used for natural diamonds. Growth-related features can vary, but the clarity grade still describes the visibility and impact of internal and external characteristics.

How to evaluate clarity when shopping

• Use the laboratory clarity grade as a starting point, not the only consideration.
• Review the diamond’s face-up appearance whenever possible.
• Pay attention to the location and type of inclusions, especially near vulnerable edges or corners.
• For step-cut diamonds, consider clarity more carefully because the facet pattern is more open.
• Read the grading report together with cut, color, carat weight, and measurements.