Diamond Education

The 4 C's

Diamond Anatomy & Cut Quality

Arguably the most important of the 4 C’s is Cut. Especially for a round brilliant diamond, it’s far more important that the diamond be cut well than any other factor. This is because a diamond could be perfectly colorless and flawless, but if it’s not cut well, it will look dull and lifeless.

A diamond is just a fancy mirror for light, and has to be cut along specific proportions and angles so as to best reflect the light shining on the diamond back into the viewers eyes. If it’s too deep or too shallow, or if any of the diamonds angles are off, then the diamond won’t be living up to its potential.

Understanding the 4 C’s of Diamonds

When making a diamond purchase, it’s vital to have a basic understanding of the 4 C’s. These are Clarity, Cut, Color and Carat.


Clarity refers to the imperfections inside the diamond. Most diamonds have some sort of imperfections inside the diamond, and only a small percentage of all diamonds are clean enough to be considered “gem quality”. The rest are used for industrial purposes such as in tech products and saws.



Diamond Clarity Descriptions (Click to Expand)

The highest clarity rating a diamond can receive is flawless, which means there are no visible flaws internally or externally on the diamond. The next is flawless, which means that the diamond does not contain any flaws internally, but may have a polish line or other imperfection on the surface of the diamond. 

VVS- Stands for Very Very Slight – VVS1 and VVS2, graded diamonds contain very, very minor inclusions that are only visible under magnification. 

VS – Stands for Very Slight – VS1 and VS2 diamonds are slightly more included. VS1 diamonds also have very tiny inclusions and are almost always completely invisible to the naked eye. VS2 diamonds, depending on the location and also the cut of the diamond might have inclusions that are very slightly visible to the naked eye.

SI – Stands for Slightly Included. SI1 diamonds have a small feather or other light inclusion. Most brilliant shapes like Round and Oval diamonds don’t have eye visible inclusions with an SI1 grade, unless the inclusion is near the center of the table. Other shapes such as emerald cut usually have slightly visible inclusions with SI1 grades, and almost all do with SI2 grades.

I – Stands for Included – I1 diamonds have relatively large inclusions that will likely be somewhat eye visible depending on the location of the inclusion and the cut and faceting of the diamond. I2 and I3 diamonds are exponentially more included with I2 and I3 diamonds having very obviously eye visible inclusions.  But even within these categories the variance and range of inclusions can be huge, since these are the broadest categories in terms of diamond clarity.


As mentioned above, cut is vitally important to any diamond, and diamonds come in all shapes and sizes. Each shape has it’s own ideal factors for cut to maximize the brilliance and sparkle of each diamond.

Diamond Cut Descriptions (Click to Expand)

Cut is arguably the most obvious of the 4 C’s right after the carat weight. If a diamond isn’t cut well, it is usually obviously visible when compared to a well cut diamond. Depending on the shape of the diamond, there are various factors that play into what constitutes a well cut diamond. For a round brilliant diamond, cut is more standardized, and GIA reports come with a cut grade. For other shapes, however, there are many factors that need to be checked to make sure a diamond is cut well.

One of the most important components of cut is the depth of a diamond. While it’s important that a diamond isn’t too shallow, with a depth percentage below 55%, but it is even more important that a diamond isn’t too deep, with a depth ratio over 65% for round and oval diamonds, and a depth over 70% for most other shapes. This is important because if a diamond is too deep, it will appear dark and lifeless in the center of the diamond, and the diamond will appear much smaller than well cut diamonds of similar carat weight, since most of the weight is hidden below the face of the diamond.


The color scale for diamonds ranges from D, which is completely colorless, to Z, which is visibly colored. Only diamonds with a slight yellow or brown tint (the most common diamond tints) are graded on this scale. A diamond that exhibits any other color, however faint, is graded as a “fancy color diamond” such as pink, blue, or green. 

Diamond Color Descriptions (Click to Expand)

DEF – A D color diamond is completely white and without any discernible tint or hue. E and F colors are pretty close and also considered to be colorless.

G-H: G to H colors are considered interchangeable with the term white diamonds. They are one of the most commonly used colors for high end yet affordable jewelry in the United States. They may have a very faint tint of color when seen loose in a color card, but appear very white when set. To most people these will appear pure white and offer a much better value than D-F colored diamonds.

I-J: Considered “Off White”, IJ colored diamonds have a slightly more visible tint of either yellow or brown when viewed loose in a color card, but when set they usually appear to be very white as well. This range is considered by the budget oriented to be the sweet spot, where diamonds still appear very white but are significantly cheaper than DEF colored diamonds. For round diamonds for example a J color diamond can be as much as half the price of an F color diamond with all the other specs exactly the same.

K-L: K to L is where color tint starts to become a bit more obvious in diamonds mounted in jewelry. While they are not considered yellow or brown by any means they do have a slight hue that is noticeable to the trained eye.

M-Z: M to Z colored diamonds have an obvious visible yellow or brown color to both trained and untrained eyes. These color diamonds are much less common in high end jewelry and engagement rings unless you get to the very end of the scale where they transition into “Fancy Yellow” or “Fancy Brown” colors where the diamonds have a very dominant yellow (canary) or brown (chocolate or champagne) color that is considered desirable and a premium product to some.

Carat (Size)

One of the most visibly apparent and talked about factors of a diamond is the size, which is the carat weight. Carat refers purely to the weight of a diamond, with 1 carat equal to 200 grams. However, diamonds with the same carat weight can often look very different visibly, since the face up milimeter size depends a lot on the depth and angles of the diamond.

Diamond Sizing Descriptions (Click to Expand)

The carat weight, which refers directly to the weight but is often directly linked with the visible size of a diamond has arguably the largest effect on the price of a diamond. Since larger diamonds are much more rare than smaller diamonds, the price of a larger diamond increases exponentially, which means a 2 carat diamond will cost more than 2 times the price of a 1 carat diamond, with all other factors constant. The price also jumps significantly at the magic numbers of 1 carat, 1.5 carat, 2 carat, 2.5 carat etc., with a .90pt diamond generally significantly cheaper than a 1.00 carat diamond, even though the visible look is often very similar.