Diamond Clarity Ratings
It was the De Beers 'A diamond is forever' campaign that truly established the position of the diamond as the most popular gemstone. However, the seed of romanticism of the diamond stone was sown long before that. The glorious tradition that would transcend time took root when Archduke Maximilian of Hamburg and Mary of Burgundy exchanged diamond rings at their engagement in 1477.
Diamond Grading
While buying diamonds, most people base their decision on size and sparkle. However, similar stones with a large disparity in price leave us flummoxed. To understand this we need to look at the grades. The value of a diamond is estimated according to the four C's of diamonds: clarity, color, carat and cut. Richard T. Liddicoat of the GIA (Gemological Institute of America) proposed and developed the GIA Clarity Grading System in 1952. Over time, several changes have been incorporated into the system. Most diamonds are graded according to the GIA chart, which considers minute differences while categorizing diamonds. Among the different qualities the chart is graded on, clarity, color and cut are qualitative values, whereas carat, which is the weight of the diamond, is a quantitative value.
Diamond Clarity Ratings
To the uninitiated, diamond clarity would mean how clear a diamond is to look at. However, the explanation of diamond clarity goes much deeper than that. There are several minute formations within a diamond, called inclusions, often not visible to the naked eye. These inclusions, along with surface defects, called blemishes, reduce the value of the diamond. Inclusions are the outcome of events that took place while the diamond was forming. They might be in the form of crystals of a foreign material, or another diamond crystal, or structural imperfections such as tiny cracks. Slight inclusions usually do not affect a diamond's sparkle. It is only when these 'clouds' are large, that they can affect a diamond's ability to transmit and scatter light. As is obvious, the higher the clarity grade of a diamond, the more expensive it is. Those considered 'flawless' are incredibly rare.
There are several types of inclusions and blemishes which affect the clarity ratings of the diamond. Inclusions may be in the form of clouds, bearding, feathers, cleavage, included crystals or minerals, cavities, knots, and internal graining. Blemishes include pits, polish lines, nicks, grain boundaries, scratches, naturals, and chips. New characteristics that may appear on the diamond as a result of enhancement procedures, such as laser lines, are also considered inclusions and/or blemishes.
The following table is the currently used GIA diamond clarity scale. The six categories and their eleven grades are:
| Category | Flawless | Internally Flawless | Very Very Slightly Included | Very Slightly Included | Slightly Included | Included |
| Grade | FL | IF | VVS1, VVS2 | VS1, VS2 | SI1, SI2 | I1, I2, I3 |
- The rarest and most expensive diamonds fall into the Flawless category (FL). They have no inclusions or blemishes visible under 10x magnification.
- The next category on the diamond clarity chart is Internally Flawless (IF), which constitutes diamonds that have no inclusions visible under 10x magnification. Diamonds with small surface blemishes also fall into this category.
- Diamonds that have minute inclusions, that even skilled graders struggle to detect under 10x magnification are awarded the grade of VVS or Very, Very Slightly Included. This category is further divided into VVS1 and VVS2.
- Those included in the Very Slightly Included category (VS) have minor inclusions that could be between difficult to somewhat easy for a trained grader to spot when examined under 10x magnification. This category is also divided into two grades: VS1 is a superior grade to VS2. In a majority of VS diamonds, inclusions are only visible under magnification. In rare cases, some VS2 inclusions are visible to the naked eye.
- The Slightly Included (SI) grade is given to diamonds that have noticeable inclusions. These inclusions can easily be identified by a trained grader, when viewed under 10x magnification. The SI category is sub divided into two grades: SI1 and SI2. These inclusions are sometimes noticeable to the naked eye.
- The last category is the Included category (I). These diamonds have obvious inclusions that are clearly visible to a trained grader under 10x magnification. Usually, the inclusions are also visible to the human eye, and can decrease the durability of the stone. This category is divided into three grades: I1, I2 and I3. Large inclusions affect the sparkle of the diamond.
