Eye-Clean Diamonds: Clarity on Paper vs Clarity on the Hand

An eye clean diamond has inclusions on the report that cannot be seen on the hand. Which grades to look in and why the plot matters more than the letter.

The clarity grade on a report is decided under ten times magnification. Nobody wears a diamond under ten times magnification. An eye clean diamond is one whose inclusions exist on paper but cannot be found by an unaided eye at normal viewing distance, and finding one is the single most effective way to buy a better stone for the same money.

What eye clean means in practice

The trade uses the phrase loosely, so it is worth pinning down. A stone is generally called eye clean if, face up, in ordinary daylight, at around 20 to 30 centimetres from the eye, a person with normal vision cannot locate any inclusion without being told where to look.

That is a stricter definition than "looks fine on the hand" and a looser one than "flawless". It is the right test because it describes how a ring is actually seen.

The grades where it matters

Flawless to VVS2. Always eye clean. Inclusions at these grades are difficult for a trained grader to find under the loupe. Paying for them buys a report line, not an appearance.

VS1 and VS2. Almost always eye clean in rounds. Occasionally a VS2 in a large step cut will show a small crystal near the table, but this is rare.

SI1. The interesting grade. A good proportion of SI1 stones are eye clean, and a good proportion are not. This is where careful selection turns a saving into a genuinely better purchase.

SI2. Sometimes eye clean, especially in stones under a carat where inclusions are physically small. More often a faint something is visible at close range.

I1 and below. Assume the inclusions are visible.

Why two SI1 stones can look completely different

Clarity grades describe the overall impact of inclusions, but they combine several factors: size, number, position, colour and how easily they are seen. Two stones can receive the same grade for very different reasons.

A single small dark crystal under the table may be graded SI1 and be plainly visible, because it sits in the most exposed position and contrasts with the bright facets around it.

Several tiny white feathers near the girdle may also be graded SI1 and be invisible on the hand, because they are pale, scattered and hidden by prongs or the returning light of the crown facets.

Same grade, different outcome. The letter cannot tell you which you have.

Reading the plot

Most laboratory reports for stones over a certain size include a plotted diagram showing the type and location of the main inclusions. It is the most useful part of the report for this purpose.

Look for marks in the centre of the table. These are the ones to worry about.

Marks near the edge are usually covered by the setting or lost in the flash of the crown.

Feathers and clouds are typically white or transparent and forgiving. Crystals and dark inclusions are the ones that show.

A note reading "clarity grade is based on clouds not shown" means the stone has a general haze that may soften its brightness even though nothing is plotted. Treat it with caution.

Shape changes the rules

Brilliant cuts, with their many small facets, scatter light in a way that hides inclusions. Step cuts do the opposite. An emerald or Asscher cut has large open facets that act like windows, so an SI1 that would vanish in a round can be obvious in an emerald cut. For step cuts, most people find VS2 the safe floor.

How to check

Ask to see the stone loose, in daylight, before it is set. Look at it face up without a loupe first, then with one so you know where the inclusions are, then without again. If you cannot find it the second time, it is eye clean for you, which is the only opinion that matters.

The saving between a VVS1 and a clean SI1 of the same size, cut and colour is substantial. That money is better spent on the cut, which is visible from across a room, than on a clarity grade that is only visible in a laboratory.

Book a complimentary design consultation at the C'Garden atelier, The MET Corporate Towers, Kuala Lumpur: 010-766 7448 · hq@cgarden.com.my

C'Garden is an independent bespoke jeweller in Kuala Lumpur. We are not affiliated with, endorsed by, sponsored by or certified by any organisation, laboratory or brand named in this article. Third-party names are used only to refer factually to those organisations and their published standards. All text and imagery in this article is original work created by C'Garden.

Reference

Gemological Institute of America. (n.d.). Diamond clarity. GIA. https://www.gia.edu/diamond-clarity