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Trillion Cut Diamonds Explained

The trillion cut diamond, sometimes called trilliant cut is a triangular shape with either straight or curved sides. The curved form makes the diamond look softer.

The shape derives from the round brilliant shape, the modern form was developed during the Second World War. After the war, variations of the triangular shape were patented leading to modifications of the cut with slightly different names such as trilliant cut, trillion and trielle.

Although the triangular shape is beautiful, its development was driven by the need to get better yields from rough stones. The triangular shape closely matches the natural shape of the rough crystals which enables more gems to be cut from a given size of the rough diamond.

For buyers of diamond jewellery, triangular gems offer excellent value for two reasons. Firstly because there is less wastage in cutting, the price per carat is lower than more wasteful shapes. Secondly, the shape has a perceived size advantage over the more popular round brilliant cut shape.

How To Choose The Ideal Trillion Diamond?

The triangular shape needs to be cut with proper proportions to look pleasant to the eye. The need for good shape means choosing a stone with all three sides of equal length, a 1:1:1 ratio. Some pieces of jewellery can support a slightly longer or broader stone but rings, in particular, need to be well-proportioned.

Many fancy cut diamonds can be forgiving in terms of their polish and symmetry. Trillion cut diamonds need to have good polish and proportions to look their best. Look out for diamonds with a cut grade of Good or better.

Get The Depth Right

Trillian shape diamonds have a shallower depth than most other cuts, typically around 35-45%. This means that the diamond is cut wider, carat for carat than other shapes, giving a perceived larger sized gem. There is a trade-off here, the fire and brilliance of the cut diamond are dependent upon the depth so a wider, shallower stone will have reduced brilliance and fire.

Smaller stones are often cut relatively shallow (less than 35%) and are used as surrounds to larger diamonds.

If you are buying a solitaire style ring with a trillion diamond, choose a deeper cut of around 44% to create the best compromise between perceived size and the beauty of the fire and brilliance attained with a deeper profile.

Count The Facets!

Trillion diamonds are cut with a carrying number of facets, the more facets in the gem, the more prominent the sparkle. Smaller diamonds, cut as accent stones to support another larger gem, usually have 31 sides. A larger diamond destined for use in a solitaire setting will usually have 50 facets.

Colour And Clarity For Trillion Diamonds

The trillion shape is not good at hiding flaws, although a well-cut gem with excellent fire and sparkle can go some way to conceal inclusions. As a rule of thumb, look for diamonds with a clarity grade of SI2 or better. Check the diamond carefully to make sure that any inclusions are not easily visible when looking at the gem from the top.

Colour grade is a matter of taste as well as budget. If your taste is for a white looking stone, go for a colour grade that is a minimum of H. If your preference is for a warmer colour, a lower colour grade will be acceptable.

How To Choose The Setting For Your Trillion Cut Diamond?

Perhaps the most crucial point when choosing a setting for the triangular trillion cut is to select a setting that can protect the relatively fragile tips of the diamond from impact damage. Impacts on unprotected points can chip or even cause the gem to shatter.

Choose a three-pronged V-setting to give physical protection to the diamond's corners. When buying the finished ring, check that the edges of the diamond have not been damaged during the setting process. A good jeweller will have the skill to ensure this does not happen.

A trillion diamond can look spectacular as a halo or a solitaire. When set into a halo design, the central stone will tend to look a little more substantial due to the surrounding diamonds and will have a softer look. A solitaire can suit larger diamonds where the gem is large enough to impress on its own.

A trillion diamond in a ring is usually worn with the wider face toward the hand and a point toward the ends of the fingers. This orientation has the effect of lengthening the fingers, making them look a little more delicate. Rings for men tend to have the stone set with the point toward the hand, giving a more chunky, masculine look.

If you choose a white coloured diamond, then a white metal setting will complement the colour and make it visually whiter. By contrast, if a warmer, yellower effect is desired, choose a yellow gold setting to enhance the warmth of the diamond.

A trillion diamond will always look unusual and somewhat avant-garde. The shape alone will impress viewers. The trillion cut lends itself to unconventional designs that will not be seen on any other hand.

Choosing a trillion diamond enables the buyer to buy a larger carat weight diamond due to the economies from the cutting and, at the same time have an even more visually impressive piece due to the perceived size advantage over conventional round diamonds.

Modern cutting techniques give brilliance and fire to equal round cut diamonds, giving the trillion a rare appeal at a relatively low price.