Princess cut diamonds are generally thought of as square, although they can in fact be quite rectangular too. When looked at from the top, the diamond’s facet structure is divided in to four quadrants. This is the result of the faceting on the rear of the diamond. The shape at the back is a little like a pyramid. Because of this pyramid type shape, the general diameter of princess cut diamonds is less than in some of the other cut types like the round brilliant cut or the Cushion brilliant cut diamond. This additional volume adds weight in the back of the diamond. The result is a diamond of less width weight for weight when compared to one of the “Brilliant” type cuts.
The Best Princess cut diamonds.
Typically princess cut diamonds have a lower crown with a larger table facet than many other popular cut options. For example a Round Brilliant Cut diamond with “Excellent cut” will have a main top facet (table facet) equal to around 57% of the diamond’s total width. A well cut princess cut on the other hand, can often have a table facet that is over 70 % of the diameter. These measurements really matter, as they lead directly into how much of the crown of the diamond remains to offer a return in light refraction, the “sparkle” if you like.
As with all diamonds, a princess cut diamond’s diameter is affected by its proportions. A low shallow crown with a larger table facet, combined with shallow pavilion (rear part below the girdle edge) will result in a wider diameter, assuming the girdle edge is not too thick. As with all the fancy cut diamond designs, getting the balance between size in mm terms and the correct proportions is critically important if you want a great looking diamond. A bigger size may seem like a good idea, however it can come as a trade off for cut performance. Most people want a great looking diamond, so this proportion issue cannot be overlooked.
Low cost princess cut diamonds will often suffer from issues relating to the symmetry of their cut. For example, they may be off square, rhombic and or have an off centre pavilion. This is where the back of the diamond is lopsided. A diamond with these issues should be avoided if the finished ring is to look its best.
Typically 1.00 ct princess cut diamonds will reach 5.5 mm in width and a 2.00 ct stone around 7 mm (or slightly under) if the diamond has been cut to its best advantage.
Stunning examples of princess cut diamonds from 1.00 ct to over 3.00 ct can be seen in our Princess cut diamond ring section.