Round Brilliant Cuts

Round brilliant cut diamonds are by far the most popular and the most in demand. They are of all shapes 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 scintillation. Go to the section on proportions to learn more about how important proportions are in this shape.

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 a long stone and a stubby. The diamond on the left weighs 1.17ct. The diamond on the right weighs 1.33ct. It is considered stubby and it also happens to be cut very deep. Hence it looks smaller.

Here's three examples of different rectangular emerald cuts. The last one is almost square while the first one would be considered lean.

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 "preferred" length to width ratio's, there are many girls who, after looking at all the different shapes of pear, decide they want one that is wide along the top and not so long. It is a stone that would fall out of the "preferred" category, but if it's what she wants... GET IT! You'll pay less for it too.

2. Most fancies have bowties:

Every fancy shape except for your 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 on how deep or how shallow the pavilion is cut on that stone. <To understand more about pavilion depth, go to the chapter of this site on "Proportions".>  All these shapes have bowties to some degree. Some are more faint and some are more noticeable, but if the bowtie turns you off don't get these shapes! Every now and then I help someone who has their heart set on a marquise cut, but refuses to buy a marquise with a bowtie. This person is in a catch 22 and will never get engaged! 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's 2 examples of what a bowtie effect looks like in a diamond. Notice the bowtie across the "belly" of these 2 stones? It really does look like a bowtie!

Fancies are cheaper!

Remember, when it comes to engagement ring sizes you can (in most places) pick up the fancy cuts for less money. Rounds are highest in demand and get the highest dollars.

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 brilliants, and if you are in the market for a "princess cut", but the jeweler can only find you a gorgeous radiant cut, BUY IT! The reason I say this is because when they set these diamonds the prongs go in the corners anyway, so no one really knows for sure (after it's set) whether it's a princess or a radiant!

How can I determine the cut quality of a fancy? What are it's proper dimensions?

While top gemologists and scientists are still trying to determine what the "best" is in rounds, it seems like fancies have been left on the wayside.    We have an  instrument called the BrilliantScope that will measure a diamonds white light return (brilliance), colored light return (fire) and the sparkle of the diamond (scintillation).  Scintillation is the discussion of white and colored light moving within the diamond as observed with the eye as the diamond is rocked or moved before the observer.  So while there is no organized cut grading system for fancies all of my clients will be able to view the stones results under the BrillianceScope™.  To see an example of BrillianceScope results on a diamond check out this link.

Bottom line with fancies:

Fancy cuts really are beautiful stones. Don't let the bowties discourage you from getting these. When they are cut right, they really are gorgeous. Fancy shapes can even look better than rounds when you start getting into carat weights that are over 2 carats. If I think of more tips on fancies I can share I'll be adding them to this page.