Much like a fingerprint is unique to every individual; clarity characteristics and/or identifying blemish features are to a diamond – no two diamonds are alike. These two important distinguishing characteristics are classified as blemishes and inclusions. Blemishes are confined to a diamond’s surface. Inclusions are either totally enclosed within the diamond or they extend into the stone from its surface; surface reaching inclusions not only effect clarity but also can have an effect on the durability and appearance (light distribution) of the diamond. For example: a diamond with a large surface reaching inclusion (feather) on the girdle can present more of a durability problem than any other inclusions because a hard knock can make the surface reaching inclusion (feather) bigger. In lower grades such as Si2 and below, one must be careful that a diamond’s clarity characteristics don’t negatively impact its light reflective properties. As light enters a diamond, it is reflected in and deflected out of the stone back to the viewing eye. Heavy inclusions can potentially interrupt the flow of light through the diamond and a part of the light reflected may be lost which can affect the appearance of the diamond.
The clarity grades are as follows:
- Flawless (FL): No visible inclusions or blemishes are 10x magnification.
- Internally Flawless (IF): Only minor surface blemishes present under 10x magnification and no internal or surface reaching inclusions. Blemishes can be removed to give the diamond a Flawless (FL) clarity grade.
- Very Very Slightly Included (VVS1/VVS2): Contain minute inclusions difficult to find at 10x magnification. The inclusions in a VVS diamond are extremely hard to see in the face-up position or they might be only visible through the pavilion.
- Very Slightly Included (VS1/VS2): Contain minor inclusions that range from difficult (VS1) to somewhat easy (VS2) to find at 10x magnification.
- Slightly Included (SI1/SI2): Contain noticeable inclusions that are easy (SI1) or very easy (SI2) to see under 10x magnification.
- Included (I1/I2/I3): Contain obvious inclusions that are obvious to see under 10x magnification.
Five Clarity Factors
Five factors determine the overall impact that an individual clarity characteristic has on a stone’s appearance and grade. Those factors are:
- Size: Size has a lot to do with how easy it is to see a clarity characteristic. Commonly, the larger the more visible a clarity characteristic is, the lower the diamond’s clarity will be.
- Number: More clarity characteristics can mean a lower grade, but also take into effect the reflection of an individual inclusion throughout the diamond.
- Position: Inclusions are most visible when they’re located directly under the table, whereas inclusions under the crown facets or near the girdle are usually more difficult to see.
- Nature: The nature of a clarity characteristic tells you whether it’s an inclusion or a blemish, and if it poses any risk to the stone.
- Relief: Relief or color of the inclusion can affect visibility of a characteristic as much as its size does. Most diamond inclusions are white or colorless, but inclusions can come in any color some are black, brown, red…etc. Since colored inclusions are easier to see and can be more prominent, they might lower the clarity grade more so than a colorless inclusion.
Which Clarity to Choose?
While Flawless and Internally Flawless diamonds are the rarest and most expensive, a diamond does not have to be flawless to be beautiful. In actuality, eye-clean diamonds within the VS1 through Si1 clarity grades are excellent choices for both value and appearance. For those on a slightly tighter budget an SI2 quality diamonds can be satisfying and much more affordable. Often, clients will opt for Vs2-Si1 clarity ranges in exchange for a higher cut and/or color grade. This combination frequently results in a beautiful, lively diamond with imperfections detectable only upon close inspection.
It's also important to take into account the design and faceting of a diamond to make the right decision regarding clarity. Modern, brilliant faceted diamonds tend to hide imperfections better than other types of stones. The many facets, reflections and reflections of reflections in these diamonds tend to mask imperfections and make it harder for the eye to make out inclusions. Step cut faceted designs such as Emerald Cuts and Asscher Cuts and vintage faceted designs, because of their large broad facets can make inclusions easier to see especially if inclusions happen to be on top of a large facet.