Perhaps you’ve heard that diamond cut is one of the defining features of a diamond, but what exactly does “ideal cut” mean, and can a diamond be cut too deep or too shallow?
Diamond Cut Defined
Cut is one of the four major quality characteristics (the 4 Cs) of a diamond and should not be confused with shape, which can be round, heart, oval, etc.
Diamond cut refers to how many facets the stone has, what their proportions are and how proportional the different parts of the diamond shape are to each other.
What Is an Ideal Diamond Cut?
When light enters a diamond, how the light is bent and reflected depends on the arrangement of the stone’s facets.
Therefore, the way a diamond is cut greatly affects its appearance.
The term “ideal diamond cut,” used mostly when discussing round shaped brilliants, refers to a cut with such proportions that the diamond can exhibit maximum brilliance and sparkle.
The closer your diamond is to this ideal, the better it will look and the more expensive it will be.
What Does “Deep Cut” Mean?
The so-called ideal diamond cut dictates what the optimal depth of a round shaped stone should be.
(Depth, or height, is the vertical distance from the stone’s flat top, also called “table,” to its pointed bottom.)
This optimal depth is one of the prerequisites for maximum brilliance.
When a diamond’s depth is too high relative to the stone’s width, it is said that this diamond is cut too deep, and its cut is often referred to as “deep cut.”
Why Is a Deep Cut Problematic?
As you might guess, a deep cut detracts from the brilliance and sparkle of a diamond.
Stones that are cut this way look less lively and have lower brightness compared with more proportional diamonds. The deeper the cut of the stone, the duller it looks.
Another problem with deep cuts is that when such diamonds are set in a mounting, they look smaller than ideal-cut diamonds of the same carat weight.
This is so because in order to achieve a greater depth, the cutter has sacrificed some of the stone’s width.
When the diamond is put in the setting, the additional depth is hidden in it, and the only part visible is the diamond’s top, which is smaller than normal.
Can a Cut Be Too Shallow?
A diamond can also be too shallow – such stones are called “spread diamonds.”
Some stones are often cut this way to make them look bigger.
However, the illusion of size comes at the expense of reduced brilliance and sparkle.
In general, whenever a cut deviates from the ideal proportions, some of the beauty of the diamond is lost.
A number of standards have been created for the proportions of the ideal cut, and these guidelines differ slightly from one another. We are not going to delve deeper into them as the standards can get pretty detailed, and it’s not reasonable to expect that you will be measuring the stone yourself when buying.
The most essential information you should know is how cut is graded.
The G.I.A. (Gemological Institute of America) uses the following grades: Excellent, Very Good, Good, Fair and Poor. You can check the cut grade in the diamond’s certificate.
Generally, if the cut is graded Good and higher, you shouldn’t be concerned about it.
Fair is a so-so grade, but such a stone will likely be more affordable, so if price is very important to you, this cut may be a reasonable tradeoff between beauty and money.
Avoid diamonds whose cut is graded Poor as their appearance will be severely lacking.
Diamond Cut Buying Advice
Remember, cut is extremely important for how your diamond will look – it affects brilliance and sparkle, which are the main reasons why you buy a diamond in the first place.
Do not settle for a poorly cut stone just because it is very cheap – there is always a reason for the low price.
Because grading cut involves a detailed and complex evaluation, which you cannot do on your own, it is very important to buy a diamond that is certified so you can see the grade of its cut in the grading report.
And while we are at it, do make sure the certificate is issued by a reputable organization such as the G.I.A.
Where to Buy Diamonds and Diamond Jewelry?
For diamond jewelry, we highly recommend James Allen because it shows real photos and videos for each diamond so you can take a 360-degree look at any stone before buying it.
For colored diamonds, we recommend Leibish & Co., which specializes in fancy color diamonds (use code JewelryNotes200 at checkout to get a 5% discount).