What is an ‘eye clean’ diamond?

Being ‘eye clean’ affects the clarity and quality of a diamond, which will alter the price of any stone. If a diamond is ‘eye clean’ it does not visually show any inclusions or blemishes on the surface or interior when viewed with the naked eye. The diamond may feature an impurity, but it may only be visible with the use of a microscope.

The clarity of a diamond is one of the 4 Cs – Cut, Clarity, Colour and Carat - because it is one of the fundamental attributes to knowing how to judge a diamond.  Clarity becomes especially important if impurities are noticeable to the naked eye in diamond jewellery or engagement rings.

Clarity refers to the level of inclusions such as scratches, blemishes, pockets of air and non-diamond material inside or on the surface of a diamond.  Fewer or less obvious inclusions make diamonds rarer and more highly valued.

What imperfections can a diamond have?

Any rough diamond can suffer from interior or surface imperfections, known as inclusions or blemishes.  Inclusions may be crystals of a foreign material or another diamond crystal, or the presence of structural imperfections such as tiny cracks that appear cloudy or white. Cracks are often known as fracture lines, needles or feathers depending on the mark they leave or their cause.  Internal crystals or marks can appear as singular ‘pinpoints’ or as clusters known as ‘clouds’.

Negative factor: The size, number, colour, relative location, orientation, and visibility of inclusions can all affect the relative clarity of a diamond and therefore lower its value.

Negative factor: Some diamond inclusions can make a stone prone to shattering or vulnerable to damage.  Some inclusions impinge on the clarity of a diamond, disturbing the stone’s brilliance because they can interfere with light as it travels through it.

Positive factor: Occasionally an inclusion can be a positive addition to the gem, if for example, the diamond features a personal favourite gem or birthstone of the buyer.

There are few perfect diamonds but the ones that are are quite expensive, so jewelers will always offer stones with varying amounts of internal/external flaws. If an inclusion does not affect the stone's strength or seriously impact its appearance it should not be a big concern.

Classification of Clarity

Diamonds are graded according to the Gemological Institute of America (GIA)'s clarity scale according to how visible the inclusions are on any stone. The range of grading starts at Flawless (F) where the diamond is completely free of inclusions even under 10x magnification: ‘eye clean’ diamonds.   The grading range continues downwards to Included (I) where the diamonds have obvious inclusions visible to the human eye.

Diamond experts and professionals refer to any diamond within the Flawless (F) to Very Slightly Included 2 (VS2) categories as ‘eye clean’.  Stones on this scale represent the highest category of quality.

For example, a Flawless or Internally Flawless (IF) diamond is situated at the top of the clarity ladder and does not have any internal flaws.  This makes them closest to being perfect, and they are therefore extremely rare and as such command a justifiable premium.

Providing the inclusions are not too visible to the human eye, the Slightly Included 1 (SI1) category could offer very good value for money.  Anything below this category – Slightly Included 2 (SI2) to Included (I) – will have imperfections which diminish value.

A Slightly Included 1 (SI1) diamond will generally have one medium or a few smaller inclusions. The inclusion(s) will often be very hard to identify but may be visible to the unaided eye and tend to be easily located using a 10x magnification loupe. Some categories can be classified as ‘eye-clean’ for a certain shape, even when for another shape they might be classed as non eye-clean.  For instance, even with a VS2 grading, Emerald cut diamonds as well as Asscher cut diamonds, might still show signs of impurity to the naked eye. Seventy Seven Diamonds operates a 5 point system which compares the clarity grades for each separate diamond cut, taking guidance from the GIA.

Always remember to inspect your prospective diamond, both inside and out, with the naked eye and using a 10x microscope in order to review any inclusions.  Make sure you research what is what to determine whether your stone is ‘eye clean’.  Ask as many questions of your jeweller as you can – this way you will find the most perfect diamond for you!