Clarity · Chapter 09

Clarity, without overbuying

What the laboratory records, what the eye notices, and when an inclusion deserves a structural check.

Clarity becomes much easier to use when magnification, face-up appearance, and durability are treated as three different questions.

The scale is a laboratory judgment

Clarity runs from Flawless to Included and is assessed under controlled conditions at 10× magnification. Neighboring grades can differ under a loupe while looking identical to an unaided eye.

“Eye-clean” needs a definition

Eye-clean is useful shopping language, but it is not a laboratory grade. FL, IF, and VVS stones are ordinarily clean to the unaided eye and often cost more for rarity that cannot be seen. VS1 and VS2 are commonly eye-clean at a normal viewing distance. SI1 can be eye-clean depending on inclusion type and location; SI2 and Included grades need more careful exact-stone inspection. None of these is a guarantee—stone size, lighting, angle, eyesight, and the setting can change the answer.

Position and relief shape visibility

A dark crystal beneath the table may draw attention more readily than a pale inclusion near the edge. Reflections can also make one characteristic appear in several places even when the plot shows it once.

Durability is a separate question

A surface-reaching feather, cavity, very thin girdle area, or feature near a vulnerable point may deserve professional review. The inclusion name alone does not establish risk; its size, position, orientation, and setting all matter.

Transparency is not captured by the label alone

Clouds, graining, and dense groups of features can sometimes affect how crisp or transparent a diamond appears. Read the comments and request slow, neutral imagery rather than relying on the plot’s apparent busyness.

Worth remembering: Choose for visible appearance and sound structure—not for the rarity of a label you cannot see.

Essential language

Eye-clean: A non-standard description meaning inclusions are not visible under stated unaided viewing conditions.
Relief: How strongly a clarity characteristic contrasts with the surrounding diamond.
Feather: A separation within the diamond that may appear white, transparent, or reflective.
Cloud: A group of tiny pinpoint inclusions that can create a hazy appearance.

Questions to take with you

Is it clean face-up at a normal viewing distance?
Which characteristic set the grade, and where is it?
Do the comments mention clouds or graining not shown?
Does any surface-reaching feature deserve a durability review?