6 250 25
8 333 33.3
9 375 37.5
10 417 41.7
12 500 50
14 583 58.3
15 625 62.5
18 750 75
20 833 83.3
21 875 87.5
22 916 91.6
24 999 99.9% OR HIGHER


800 80
900 90
925 92.5
999 99.9 OR HIGHER


850 85
900 90
950 95
999 99.9 OR HIGHER



Shapes of Diamonds

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Carat is often confused with size even though it is a measure of weight. The cut of a diamond can often make it appear larger or smaller than its actual weight. Jewelers often refer to the carat weight of diamonds in terms of points. There are 100 points to a carat (similar to 100 pennies to a dollar). If a jeweler says a stone weighs 25 points, he or she means it weighs 25/100 of a carat, or ¼ carat.

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Since larger diamonds are more rare than smaller diamonds, the value rises exponentially with carat weight.


A Diamond's Cut

Cut actually refers to two aspects of a diamond. The first is its shape (round, marquise, etc) the second is how well the cutting has been executed. A diamond's cut will most certainly influence its fire (the lovely rainbow colors that flash from within) and brilliance (the liveliness and sparkle), as well as its perceived size and even, to some degree its apparent color. Different cuts reflect light in different angles. A diamond must be cut in a geometrically precise manner to maximize its brilliance.


Diamond Clarity

All diamonds have identifying characteristics, but most are invisible to the naked eye. To view a diamond, experts use a 10x magnification loupe, which allows them to see the appearance of tiny crystals, feathers, or clouds. These natural phenomena are called “inclusions”. Inclusions are also referred to as internal characteristics of the stone. External characteristics of a stone are referred to as “blemishes”. Blemishes can occur when a diamond is being cut, polished, or set into a mounting. A diamond’s clarity is a measurement of how flawless the stone is. The more flaws a stone may possess, the lower the value and visa versa.


Diamond Color

Many experts name color as the number one consideration in choosing a diamond. A diamond’s color is graded on an alphabetical scale from D-Z, with D being absolutely colorless and Z being light yellow. Beyond “Z”, a diamond is considered to be an exotic or “Fancy” color (diamonds occur in every color of the rainbow).



Diamond Color Scale

Since color differences can be so subtle, they are impossible to determine by the untrained eye. To grade a diamond, gemologists often place it on a white background next to another diamond that has been previously graded. If all other factors are equal, the less color in a diamond or the higher the color rating, the more valuable a diamond becomes. Likewise, as the amount of color increases, the price of a diamond decreases (though this does not necessarily reduce the beauty of a diamond).



The diameter is the width of the diamond as measured through the girdle.



The table is the flat facet on the top of the diamond. It is usually the largest facet on a cut diamond. The table also plays a role in determining sparkle and fire.


Table Percentage:

The table percentage is the value which corresponds to how the diameter of the table facet compares to the diameter of the entire diamond. For example, a stone that has 50% table has a table which is a 50% as wide as the diameter of the diamond. In terms of finding the table percentage of a round stone, gemologists usually calculate the table percentage by dividing the diameter of the table by the average girdle diameter.



The crown is the upper part of the diamond that lies above the girdle. The crown determines the scintillation, or sparkle of the diamond, as well as the fire, or dispersion.



The girdle is the outer edge and the widest part around the diamond. The girdle forms a band around the stone and protects it from chipping. At times, the girdle could be too thick and add unnecessary weight to the stone.



The pavilion lies at the bottom part of the diamond, below the girdle. It plays the most important role in determining the brilliance.



The culet is the final facet to be polished on the diamond. It is a tiny final facet that diamond cutters often add at the bottom of the diamond's pavilion. The purpose of the culet is to protect the tip of the pavilion from being damaged. After the diamond is set in jewelry, the actual setting provides the pavilion with enough protection. However, modern shapes rarely have a culet at all, or a very small one.



The depth refers to the height of the stone from the culet to the table. It is usually measured in millimeters.



The facets are the flat, smooth faces on the surface of the diamond. A facet allows light to enter the diamond as well as reflect off its surfaces from the different angles. They aid in creating the different colors and light that diamonds are known for.