Princess cut

The Princess cut diamond shape is the second most popular cut shape for diamonds and accentuates a diamond's fire rather than its luster. The top of the diamond is cut in a square shape. The princess cut is a relatively new diamond cut, having been created in the 1970’s. It has gained in popularity in recent years as a more unique alternative to the more popular round brilliant cut, in which the top of diamond is cut in a round circle. The diameter of the princess cut is usually smaller than that of a round cut, and the height is usually longer. The princess cut is sometimes referred to as a "square modified brilliant," as it combines the brilliance of a round cut with an overall square or rectangular appearance.

The square princess cut diamond is usually less expensive than a round brilliant cut diamond of the same carat weight[1][2] because a diamond cutter usually doesn't need to shave off as much diamond weight from their rough diamond. Thus when making a princess cut diamond they can usually make it at a higher carat weight than if they were to make a round brilliant diamond instead. The demand for round brilliant diamonds is generally greater than the demand for a princess cut diamond as well. But the ability to retain more crystal weight makes this shape popular amongst diamond cutters.

The American Gemological Society (AGS or AGSL) is currently the only lab that grades the Princess cut. An AGS cut grade of "0" is the best princess diamond cut you can get and is considered an "ideal" princess cut diamond. Such a diamond demands a price premium over other princess cut diamonds because it has better light performance. Generally the best princess cut diamonds will have a table of 62%-68%, crown height of 10%-15%, and a total depth of 64%-75%.