Diamond Grading

While there are many different factors that gemologists take into account when determining the value of a diamond, the most important considerations are the 4 Cs of a diamond (cut, color, clarity, and carat). These standards were set into place to make it easier for people to gauge the value of a diamond either when selling or buying.

When you sell your diamond online, diamond buyers will use these factors (especially during the initial valuation) to determine the price of your diamond. Once the diamond goes in for the final valuation, diamond experts may use other considerations in determining the value of the stone but these four are the main ones you should concern yourself with.


It is worth noting here that when we talk of a diamond’s cut in relation to its value, we don’t mean its shape (e.g. round, princess, cushion) but rather the diamond’s proportions and how well it is able to transmit light. When a diamond is able to disperse light perfectly through its top facets, you’ll notice that it has more of a sparkle than lesser quality cut grades. A diamond’s cut is a bit more complicated to analyze but it definitely affects the face value of a diamond. There are 5 cut grades for diamonds from Poor to Excellent.

When determining the cut grade of round brilliant diamonds (the most common shape of diamonds in the market), diamond experts look at the proportions of the diamond’s facets and how it affects the diamond’s brightness, how white light is dispersed into the colors of the rainbow (fire), and its sparkle (scintillation).


The clarity of diamonds ranges from Imperfect (I1, I2, & I3) to Flawless (FL). Clarity is based on the number of flaws visible under 10x magnification. A diamond classified under the I1 to I3 range has very obvious inclusions when viewed under 10x magnification and a diamond under the Flawless range does not have any visible flaws or blemishes even under 10x magnification. The price of a diamond is greatly affected by its clarity. Blemishes and inclusions can affect the overall quality of a stone, which is why flawless diamonds are valued very high.


Carat (Weight)

Carat simply refers to how heavy a diamond is. 1 carat (metric) is equal to 200 milligrams. When measuring the weight of diamonds, a carat is divided into 100 points. This allows for a more exact measurement of a diamond’s weight, especially when measuring diamonds that don’t have a round number carat value. For example, a diamond that has 25 points is .25 carat.

Diamond price can significantly increase the heavier it is, especially if it is above a carat. This is especially true because many people prefer larger diamonds to smaller ones. However, since cut, clarity, and color also have a hand in determining the value of a diamond, 2 similar diamonds with the same carat weight can have vastly different values depending on how flawless and clear they are, as well as how well they are cut.


Since colorless diamonds are rare, evaluating the color of a diamond is based on how colorless it is. The GIA uses a D to Z grading system for diamond color, with D being the most colorless and Z having the most color. The closer the color value3 is to D, the less visible the color is. A colorless diamond is worth a lot more than one with visible color even if the latter has a higher carat weight than the former.




Near Colorless Diamonds








yellow tinge


Light Yellow