Clarity · Chapter 15

Inclusions at the expert level

How type, position, relief, extent, and surface reach matter more than an alarming name.

The clarity grade compresses a complex internal landscape into a shared scale. Expert reading reverses that compression: it asks which feature set the grade, how it presents, and whether it affects appearance, transparency, or structure.

Five factors establish clarity impact

Laboratories consider the size, number, position, nature, and relief of clarity characteristics under standardized conditions. A small dark crystal beneath the table may be more visible than a larger low-relief feather near the girdle; the inclusion name alone predicts neither grade nor beauty.

Clouds and pinpoints are cumulative

A cloud is a grouping of minute features, often pinpoints, that may be harmless and difficult to see. Dense or widespread clouds can scatter light and reduce transparency. Comments such as “clarity grade is based on clouds that are not shown” deserve exact-stone review, not automatic rejection.

Graining and twinning record growth

Internal graining can appear as lines, reflective planes, or hazy areas related to irregular crystal growth. Twinning wisps combine features associated with a change in growth direction and are common in some crystal types. Their extent, relief, and effect matter more than their category name.

Surface-reaching features need context

Feathers, cavities, knots, indented naturals, and naturals may reach the surface. Location near a point, corner, very thin girdle, or setting seat can matter to durability or finishing. Many are stable; significant features should be assessed in three dimensions by a qualified professional.

Reflections can multiply one inclusion

Pavilion facets act as mirrors. A single crystal or feather can reflect around the stone and appear more numerous than the report plot suggests. Rotate the diamond slowly to distinguish the original feature from its reflections and judge whether the pattern distracts face-up.

Separate rarity, visibility, and risk

A higher clarity grade can be rare without looking different to an unaided observer. Conversely, an eye-clean stone may contain a feature that deserves a setting or durability review. Make three separate judgments: visual cleanliness, transparency, and structural suitability.

Worth remembering: Clarity is most useful when the grade leads back to the exact characteristic and its real consequence.

Essential language

Relief: The degree of contrast between a clarity characteristic and the surrounding diamond.
Twinning wisp: A series of inclusions associated with a change in a diamond crystal’s growth direction.
Knot: An included diamond crystal that reaches the surface of the polished stone.
Indented natural: A portion of the original crystal surface that dips below the polished surface.
Internal graining: Lines, curves, or reflective features related to irregularities in crystal growth.

Questions to take with you

Which characteristic set the grade, and where is it in three dimensions?
Is the feature itself visible, or am I seeing reflections of it?
Do unplotted clouds or graining affect transparency?
Does any feature reach the surface near a vulnerable edge or setting seat?
Am I paying for rarity beyond what changes unaided appearance?