Cut
Like other fancy-shaped diamonds, certification agencies like the GIA do not grade trillion cut diamonds for cut. The structure of this cut is simply too complex and unique to create a universal standard around cut quality. So for cut, your choice should be guided by parameters around some key features and then personal preference.
The generally accepted guidelines around a more ideal cut for a trillion cut diamond break down as the following:
- - Depth: 32-48%
- - Table: 50-70%
- - Length to width ratio: 1.00 - 1.10
The most helpful gradings on the certificate that pertain to cut are the symmetry and polish grades. Choosing a stone with excellent or very good symmetry and polish within the previous stone parameters is a good indicator of a well cut diamond.
For symmetry, the facets on the right and left halves of the stone should have the same shape and size. All the points should meet and there shouldn’t be any missing or extra facets. This layout of facets should perfectly play off of a not-too-shallow depth and mid-sized table in order to reflect a fantastic brilliance and fire throughout the stone.
Color
A trillion cut diamond is able to nicely hide color when it’s a well-cut stone. If it’s not cut well, and especially if the depth is too shallow, more color will show through. Ultimately, how much color a diamond exhibits is a personal preference and can be altered depending on the type of metal you use for the setting.
If you’re set on a white diamond look, you’ll want to choose a cool metal like platinum or white gold and stick to a diamond color grade of H or better. If warmer tones of yellow gold or rose gold are appealing, a color grade of J or better will be accentuated beautifully in those metal settings.
Clarity
Trillion cut diamonds are fantastic at concealing inclusions and blemishes. Their brilliant faceting style and unique shape allow for really nice clarity conditions. However, since the triangular cut produces three sharp points, it’s best to avoid any larger inclusions in those areas since they will make an already vulnerable part of the stone more fragile.
The best route to take for a trillion cut diamond’s clarity is to look for an eye-clean stone. Whether looking for a center stone or accent stones, an eye-clean stone means that there are no inclusions or blemishes noticeable to the naked eye. But since well-cut trillions are hard to find, you may want to consider every clarity grade from SI2 and up. This way you’ll have options for also getting a good shape and lots of sparkle.
Carat
Trillion cut diamonds are usually cut to the ideal proportions and length width ratio for the quality of the stone being cut. So a trillion cut diamond’s carat weight will not necessarily dictate how big or small it looks in person. The stone’s measurements are a better indication of the apparent size.
Finding a variety of trillion cut diamonds in differing carat weights may also be a big endeavor. While they are becoming more popular to see as a center stone, this diamond cut is far more popular being used as an accent stone. So if you’re looking for a center stone, know that trillion cut diamonds of 1 carat or larger and high quality are quite rare.