Round Brilliant Cut Diamond Set in traditional 4-claw Ring

Round brilliant cut diamonds are by far the most popular and the most in demand. Of all the shapes available, Round Brilliants are the most valuable.

The proportions of a round diamond are extremely important since all the angles stay the same around the stone. All light (when properly cut) is distributed evenly throughout the stone producing the highest amount of brilliance, fire and scintillation.

Important tips you should know about fancies.

If you are in the market for a fancy brilliant cut diamond there are a few things you need to keep in mind.

1. The length to width ratio:

Fancies come in an assortment of shapes. For example if you're in the market for a marquise, pear, square, etc. These stones come in different shapes. Some marquise' for example can be very long and narrow and some can be very short and stubby.

Here's an example of two different Marquise cut diamonds showing a long stone and a stubby stone. The diamond on the left weighs 1.17 carats whilst the diamond on the right weighs more at 1.33 carats. It looks smaller because it has been cut with a very deep pavillion, its shorter and wider hence it looks smaller.

Here's three examples of different rectangular emerald cut diamonds. The last one is almost square while the first one would be considered long and thin.

When it comes to the fancy shapes there is what is known as "preferred length to width ratio". In a marquise diamond the preferred length to width ratio is 1.75-2.25 to 1 or in short, the length of the marquise should be about double its width. When the diamond falls within this preferred length to width ratio, it's shape will be looking like it's supposed to. To get the length to width ratio on any fancy cut diamond simply divide the length of the diamond by the width. So if a marquise had a length of 10.05mm and a width of 5.70mm, you divide 10.05÷5.70 and you get 1.76 or a length to width ratio of 1.76:1. Simple enough? The following table is a chart of what the preferred length to width ratios are for the most common cuts.

Now while these may be the experts "preferred" length to width ratio's, there are many ladies who (after looking at the different shapes) decide they want one that is wide and not so long. It may be a stone that falls outside of the "preferred" category, but if it's what she really wants... GET IT! You'll pay less for it too.

2. Most fancies have bowties:

Every fancy shape except for squares and trillion cuts have what's called the "bow-tie" effect. Because the pavilion angles around the fancies vary, this produces a "bowtie" effect in marquises, pears, ovals, and hearts. How noticeable the bowtie is depends very much on how deep or how shallow the pavilion is cut on that stone. All these shapes have bowties to some degree and some are more faint than others.There is no such thing as getting a marquise that does not have a bowtie, even if it is cut "perfectly" it will still have a bowtie! Here is 2 examples of what a bowtie effect looks like in a marquise-cut diamond and a pear-cut diamond. Notice the bowtie across the "belly" of these 2 stones? It really does look like a bowtie!

Princess Cut vs Radiant Cut:

There are basically 3 different kinds of square cuts on the market. There is the traditional "emerald cut" which is the step cut. Then there are 2 brilliant square cut diamonds that are very popular on the market place. One called a princess cut and the other called a radiant cut. Both stones are extremely similar and the only noticeable difference between the two is that the princess has sharp pointed corners while the other has tapered corners. Here's an example of both.

On GIA reports these are usually described as modified square brilliants, and if you are in the market for a "princess cut" you should seriously consider square radiants as a less expensive alternative. The prongs of the setting will usually be placed over the corners of the diamond so you'll never know the difference anyway.

Fancy cuts really are beautiful stones. Don't let the bowties discourage you from getting these. When they are cut right, they really are stunning.