Last updated on March 30, 2021
The trillion is a popular cut for accent stones in many jewellery designs. However, it is also a beautiful alternative to traditional diamond cuts working as a centre stone for those looking for personalization. If you are interested in buying a diamond with a unique shape, proportions and symmetry, this trillion cut diamond guide is a must-read.
History of Trillion Cut Diamonds
Although the trillion cut may seem to have a contemporary design, its history traces back to the 18th century.
It is often said to have been developed in 1962 but, in fact, that is when the cut was trademarked by Henry Mayer Diamond Company of New York.
The initial trillion cut was developed in Amsterdam in the 18th century, however, the design varied dramatically depending on the rough form of the stone.
Inspired by the initial cut and antique triangular cuts, such as Old Mine triangular, briolette and others, as well as modern brilliant-cut facet pattern, Henry Mayer designed the modern triangular cut and named it trillion – a combination of words “triangle” and “brilliant”. Very soon, all triangular-shaped stones featuring brilliant-cut facet pattern adopted the name.
The modern trillion cut also referred to as a trillion, trilian or trielle cut, features three equal sides and 31 or 50 facets depending on whether the diamond is used as an accent stone or a solitaire. Variations of trillion cut diamonds include sharp-cornered curved and straight, round-cornered curved trillions, modified shield cuts and triangular step cuts, often with different facet counts.
Nowadays, trillion cut diamonds are most often used as accent stones to complement larger centre stones in jewellery designs, however, they also make a beautiful option in solitaire jewellery pieces, such as stud earrings, pendants and engagement rings.
Pros and Cons of Trillion Cut Diamonds
Being a unique shape, the trillion cut has both positive and negative features. However, its cons should not stop you, as they can be easily worked around.
- Being derived from the brilliant cut, trillion cut diamonds are known for having impressive brilliance and fire, meaning they are also good at hiding colour and inclusions.
- Trillion cut diamonds look larger than round or princess cut diamonds of the same carat. The reason for this is that trillion diamonds have a shallow cut and large face-up area. However, keep in mind that the trillion cut like all the other cuts has certain cut standards. This means you should not opt for extremely shallow stones because the depth of the diamond will not be enough to make the light reflect properly.
- Trillion cut diamonds are exposed to chipping at their pointed ends, especially if you happen to handle such a diamond unmounted. However, if the stone is properly set in its mounting, this potential problem should never be a concern.
- Trillion diamonds require special attention to prongs. Because of their non-standard shape, such stones need secure prongs to protect the tips from chipping and breaking. It is highly recommended having your trillion cut diamond set in V-prong. This type of prong will wrap the tips and protect them from possible damages. In case of choosing the classic prong setting, make sure the prongs are large enough to cover the tips to avoid the risk of chipping.
- Trillion cut diamonds need extra cleaning since they have less depth compared to the round and princess cuts. Because of its shallow cut, the sparkle of a trillion cut diamond can be easily dimmed by even a little dust or dirt. This means you will need to clean it more frequently to enjoy its brilliance and sparkle.
Trillion Cut Diamond Quality Guide
Unlike round diamonds, trillion cut stones do not have any specific guidelines for excellent cut quality.
The GIA (Gemological Institute of America) doesn’t provide cut grading for trillion cut diamonds due to their complex and unique structure. This means your choice should be dictated by your personal preferences and some key features.
To choose the best stone you need to pay special attention to the symmetry and polish grades listed in the certificate. Excellent or very good symmetry and polish are strongly recommended.
The facets on the right and left halves of the stone should have the same shape and size. All the points of the facets should meet, there should not be missing or extra ones. The more symmetrical the facets, the more beautiful the stone.
Also, make sure the stone is not too shallow because a too spready cut will diminish the beauty of the stone. In addition to that, it is recommended to opt for a stone with H colour or higher and SI clarity grade or better.
The cut parameters below will serve you as a general guideline in evaluating the cut quality of trillion cut diamonds:
- Depth: 32% – 48%
- Table: 50% – 70%
- Length to width ratio: 1.00 – 1.10.