What is an “eye-clean” diamond, and who decides?

ZKZ Editorial TeamMain answer · Product & gemmology desk

Eye-clean is not a grade. Laboratories grade clarity under 10x magnification, and whether you can see an inclusion without magnification depends on the stone, the lighting and your eyesight. The person who decides is, in practice, the seller, unless you check the stone yourself.

What the sources say

Fact IGI states that its traditional 4Cs assessment was not designed to judge whether a person can see inclusions, and that IGI and other laboratories do not make an eye-clean judgement.

Fact IGI cites a gemologist survey on the PriceScope community that defined eye-clean as no inclusions visible to the unaided eye, face up, in daylight-equivalent or fluorescent light, 6 to 12 inches from the eye, with 20/20 vision. By that definition IGI says round brilliants of VS2 clarity and higher are reliably eye-clean, while step cuts such as emerald cuts, and round brilliants over 3 carats, should be checked case by case.

Fact GIA says clarity grades are assigned under 10x magnification and that, of its grades, VS inclusions are "observed with effort but can be characterized as minor".

How to use this

Our advice Treat an eye-clean claim as the seller's opinion. Ask for the clarity grade, a clear photograph or video and the return terms.

Our advice Look at the stone in daylight at a normal distance, face up, before you decide.

It depends The same stone can look clean to one person and not to another, and shape matters: step cuts show inclusions more readily than brilliant cuts.

A simple test you can run

Our advice Hold the stone, or a magnified photograph from the seller, at the distance of a normal conversation. Look face up, then tilt it. If you cannot see anything distracting at that distance in daylight, the stone is clean for practical purposes. Repeat with a friend, because eyesight differs, and make sure the return period allows you to do this at home.

Uncertain The survey definition is a community consensus, not a standard. We have not verified how sellers apply the word.

Related reading: What does fluorescence mean on a lab-grown diamond report? · Cleaning Lab Diamond Earrings Without Damaging the Setting

Sources

• IGI, Diamond clarity chart with eye-clean definition
• GIA 4Cs, Diamond clarity

Fact = stated by the cited source. Our advice = editorial recommendation. Uncertain / it depends = limits of what can be said in general.