What is Diamond Clarity?
Clarity is the presence or absence of inclusions and blemishes in diamonds. Gemologists refer to these inclusions or patterns of inclusions as “identifying characteristics” and consider them to be a diamond’s unique “fingerprint.”
Diamonds are graded for clarity according to the number, size, location, and type of inclusions.
– transparent or opaque crystals called pinpoints,
– clouds that are groups of pinpoints
– internal fractures called feathers
– Internal graining (crystal growth twinning planes)
External blemishes include polishing lines, grain lines, scratches, chips, nicks, and “naturals” (part of the rough diamonds’ original surface).
Diamonds are graded by skilled professionals using natural or artificial light with a 10X loupe corrected for chromatic and spherical aberration or with a 10X binocular microscope equipped with dark-field illumination.
The GIA system has a total of 11 specific grades. They are grouped into six categories:
Flawless (FL) Nothing is visible under 10x magnification. It’s a pure diamond crystal with positively no blemishes or inclusions. Flawless diamonds are generally not used in jewelry. They will most likely develop blemishes during the wear and drop to IF or even the VVS category.
Internally Flawless (IF) No inclusions visible under 10x magnification except minor blemishes. The blemishes can be repolished to bring the clarity grade to the Flawless. The surface grain lines cannot be repolished.
Very, Very Slightly Included (VVS1 and VVS2) Inclusions are so minor (often smaller than specks of dust) that it can take hours for a skilled gemologist to find them under 10x magnification. The difference between VVS1 and VVS2 grades is in the number and location of inclusions. VVS1 diamonds typically have no more than two inclusions located on the periphery, while VVS2 inclusions can be closer to the center.
Very Slightly Included (VS1 and VS2) Minor inclusions requiring an effort to see the inclusions under 10x magnification. In step cuts, VS2 inclusions can be noticeable to a person with a sharp eye.
Slightly Included (SI1 and SI2) Inclusions are noticeable under 10x magnification.
Included (I1, I2, and I3) Inclusions are obvious under 10x magnification and, in I2 and below, almost certainly affecting diamond transparency and brilliance. Usually, these inclusions will be centrally located and noticed immediately when the diamond is examined. SI inclusions are usually evident when the stone is placed table-down on a white background but not face-up.
Most SI1 brilliant-cut diamonds are eye-clean. It is rare to find an eye-clean stone below SI1 grade. There is an occasional SI2 diamond that got a poor grade despite being eye-clean. This fact is usually reflected in the diamond’s price.
Diamonds with translucent, non-reflective inclusion or inclusions located at the girdle where prongs could cover them are desirable.
Prongs and bezels holding a stone are partially covering it. Strategically placing metal over the inclusion can hide it from the view.
There are a few things to consider. Often the inclusion is too big to be covered. Also, some inclusions make a diamond fragile, so applying the pressure with a prong during the setting can shatter the stone. And finally, sometimes, it is impossible to cover several inclusions without altering the prong’s position, which can negatively affect the jewel’s look.
An “eye-clean” diamond has no imperfections visible to the unaided eye. However, vision clarity, peripheral awareness, eye coordination, depth perception, focusing ability, and color vision vary from person to person. It makes a clear definition of “eye clean” impossible.
The traditional clarity grading system relies on the 10x magnification to define the visibility of the inclusion.
What GIA should have done is to split SI stones into three or even four sub-categories. Unfortunately, they opted for just two, opening the door for creative and very subjective opinions.
Regardless of their clarity grade, the eye-clean stones offer excellent value to the consumer.
There are only two clarity grades for most consumers: stones that look clean and those with something inside, real or imaginary.
The SI is a watershed grade for brilliant-cut diamonds making a “good SI” a sweet spot for bargain hunters.
For step-cuts, the VS2 grade is where eye-clean stones are mixed with those where inclusions stick out like a vegan at the steak dinner.
- – A knot is an exposed crystal breaking the diamond surface.
- – Abrasion is the damage from scraping or wearing away edges. Myriads of tiny chips blunt the intersections where facets meet.
- – Scratches are scores or marks on the surface caused by contact with another diamond.
- – A natural is a leftover section of the rough diamond skin that is left unpolished. Usually, naturals are on the girdle and are often mistaken for chips. Triangular marks called trigons help to identify them as naturals.
- – A nick is a small chip on a girdle or facet.
- – White or transparent polish lines left on the surface after polishing can be easily removed, usually without losing weight. A “drag line” is a deep single polish line.
- – Polish marks are hazy areas on the surface caused by excessive heat during polishing.
- – A pit is a minute opening on the stone’s surface, usually mistaken for a pinpoint or a speck of dust.
- – Grain lines are wavy ripples caused by polishing the crystal’s zone of irregular growth.
- – Wavy skin is a transparent rippled texture resulted from polishing a facet against the grain.
- – Extra facets are usually added to remove a flaw located close to the surface. Additional facets are usually located next to the girdle, where they are less visible.
- – Rough girdle is a grainy patch on the bruted girdle left unpolished during faceting.