Jun
22
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Our Article on AndersonCooper.com Figure 1: Classic Shape of Rough Diamond
The shape of a classic piece of diamond rough is called an “octahedron.” Imagine two 4-sided pyramids stuck together at their bases. Typically, that piece of rough is sawed into two pieces which are each then made into polished diamonds. Since diamonds jump in price exponentially with increased weight (well,not exactly, but see here for an explanation of diamond pricing), it makes more economic sense to saw that octahedron not down the middle, but just off center. Then the center of that piece of rough becomes the girdle of the larger polished diamond. (see Figure 2)
Don’t worry, there’s a reason why I’m boring you with all these details. Take a look at Figure 2. Try to imagine what the rough looks like after it’s been sawed through the plane represented by the black line. What diamond cut (shape) does it look like? If you guessed Princess cut, you’d be correct. A princess cut is really just a slightly faceted sawed diamond crystal. It was invented not for its beauty, but in order to minimize loss of diamond material. A Princess cut can easily have a yield percentage of rough of 80-90% Compare this with a round diamond (represented by the purple diamond in Figure 3) that will at best have a yield percentage of rough of about 40%.
For diamond crystals with less than perfectly formed corners, the cutter might choose a radiant cut or asscher cut. For diamond crystals that are slightly more rectangular, the diamond cutter will choose a rectangular shape, such as an Emerald cut.
Some naturally occurring diamond crystals look like flat triangles. That’s how the Trillion, Heart shape, and Pear Shape diamonds were born.
Figure 2: 1 Piece of Rough = 2 Polished Diamonds
Anyway, you get the idea. With the exception of the Round Brilliant Cut, all the others were created to maximize polishing yield in different naturally occurring crystal formations.
In terms of popularity, Round Brilliant Cuts are by far the most popular shape. After rounds, princess cuts are the most popular. After princess, the numbers drop pretty steeply. I found this interesting chart at Jogia Diamond’s blog. They accumulated this data through their diamond search feature on their website. The proportions are for diamonds searched, not diamonds sold.
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Comments
Hi Ira
I went out today looking at some rings in the diamond district in Manhattan with my girlfriend. It turns out she has her eyes set on Asscher shape stones. Can you send me your recommendations. She likes 1.5 carat or higher; my budget for the stone is $12,000. The diamonds on James Allen looks good but I am not sure if the Inclusions I see will be very visible to the naked eye. Please help.
Sure thing. I like this one:
www.jamesallen.com/diamonds/G-VS1-Ideal-Cut-Asscher-Diamond-1350379.asp
Hi Ira,
Your website is very helpful.
My other half and I are looking to buy a regtangular cushion or radiant diamond for a setting (TBD) but something like this:
www.jamesallen.com/mobile/item-page.asp?item=894
We are hoping to spend under $2000 on the stone and it get 0.5ct – 0.8ct.
After reading your article on fancy cut diamonds and not being able to rely only on proportions, I decided it was time to reach out to you.
I do love the crushed ice look of the “original radiant” and some cushions but I’m open to anything!
Thank you!
I also forgot to mention that the most important thing to me is that it sparkles like crazy (so I guess I need the best possible cut). I was thinking a color grade of around a G, and just as long as I can’t see the inclusions, I am happy
This is one diamond I really like but it looks a tiny but yellow, which I don’t want, but that may just be the photo:
www.jamesallen.com/mobile/diamond-page.asp?diamid=1432019
I am excited to hear your recommendations!
Thank you!
Also a nice option! It won’t look yellow.
Hey S. Thanks for the kind words. Here’s what I like for you:
www.jamesallen.com/diamonds/G-SI2-Ideal-Cut-Radiant-Diamond-1443453.asp
Hi Ira,
Fab site! I am looking for a marquise diamond in a channel setting (with baguette diamonds, as opposed to round diamonds). Wanting at least 1.5ct as the main diamond and looking for it to sparkle! I have been thinking D-E with no lower than VS2 clarity and no fluorescence. Prices seem to be quite high – am I being too picky? Could I still have a beautiful ring with lower gradings?
Hi Nicky. You can definitely go down in color and clarity and still get a stunning diamond. Here’s a couple suggestions:
www.jamesallen.com/diamonds/F-SI1-Ideal-Cut-Marquise-Diamond-1388849.asp
www.jamesallen.com/diamonds/G-SI1-Ideal-Cut-Marquise-Diamond-1026214.asp
www.jamesallen.com/diamonds/H-VS1-Ideal-Cut-Marquise-Diamond-1342714.asp
[...] course, the way a stone is cut also determines the general shape of the diamond. Some shapes you may be familiar with after browsing through various Plano, Texas stores are the heart, round, [...]