Diamond cut is the most important aspect of the 4Cs when buying a diamond. It determines the amount of sparkle and fire that a diamond will display.
So, if you want to know how to select a beautiful looking diamond instead of a dull looking one, you’ve come to the right place!
In this section, you are going to find out what is diamond cut and why it matters when you are shopping for an engagement ring. You are also going to get the real insights to selecting well-cut diamonds and how to separate the wheat from the chaff.
Let’s get started…
In essence, cut refers to how well a diamond’s facets interact with light. A well cut diamond will display superior brightness, fire and scintillation compared to one that is poorly cut.
There are 3 main attributes that affect the diamond’s overall cut quality. They are:
Many people often confuse cut to be the same as a diamond’s shape. They aren’t the same thing and it doesn’t help that many jewelers use these 2 terms interchangeably.
Cut itself can make a diamond look bigger, improve the face up color and help mask inclusions. This means you effectively get a “free” boost in the other aspects of the 3Cs (color, carat and clarity) just by having a better cut!
Check out the comparison of a perfectly cut diamond and an inferior cut diamond below. The one on the left has superb scintillation patterning and very strong light return while the diamond on the right is less lively and displays a messy contrast patterning.
I want you to click on the images to see the differences between the 2 diamonds for yourself.
The visual difference between a truly well-cut diamond and a poorly cut diamond is huge!
The thing is, a well cut diamond will have better proportions that don’t cause excessive carat weight to be hidden in its side profile. This makes the diamond appear the right size for its weight compared to another diamond that is cut deeply and faces up smaller.
Having better light return will make the diamond face up whiter since more light is reflected back into the eyes of the viewer. Lastly, well cut diamonds will display an intense scintillation and fire which can help hide inclusions under its sparkle.
Check out the following video of an I color SI1 diamond engagement ring. This diamond was personally handpicked for the best cut and sparkle. It will give you an idea of what a truly well-cut diamond looks like in real-life.
Did you know that the amazing play of light displayed by a diamond is actually governed by the laws of physics?
On a fundamental level, the amount of sparkle and scintillation is dependent on how light rays are refracted and reflected within the diamond. This is why the precise positioning and alignment of each facet matters as they act like tiny mirrors to interact with light.
In a well cut stone, a large percentage of light that enters the diamond gets reflected back into the viewer’s eyes. This gives the diamond a bright looking appearance and enhances its luster.
With less ideal diamond cut quality, light is lost through the sides of the diamond instead of being reflected back into the viewer’s eyes. This translates to a less brilliant and darker appearance of the diamond.
A gemological lab like GIA typically performs diamond cut grading by reviewing a range of parameters like the diamond’s proportions, polish/symmetry ratings, cutlet size and girdle thickness.
Watch the short video below to get a quick overview into this topic.
In a typical grading report for a round brilliant diamond, you can find a similar diagram like the example below. On this diagram, the averaged measurements of the corresponding facets are indicated.
Depending on how technical (or hardcore) you want to be, you can analyze each of these parameters and study the correlations between them. I will talk about it in advanced tutorials found on the later pages.
Now, I know most people get scared or turned off when they see a technical diagram like this. As a consumer, an easier alternative would be to simply use the GIA/AGS cut grading as a filter to pre-screen round diamonds.
For the record, I only recommend buying a round diamond with a GIA triple excellent cut grade or an AGS ideal cut grade.
Gemological labs like GIA or AGS take the proportion variations of a diamond into account when assessing a diamond’s cut grade. If any particular aspect of the cut proportions has an issue, the diamond will be downgraded and assigned with a lower cut grade accordingly.
That means even if you blindly go along with any GIA triple excellent diamond, it is unlikely for you to end up with an ugly looking stone. However, if you want to select the cream of the crop among the GIA triple excellent stones, you will need to do some extra work in filtering your choices.
But first, I want to show you the visual appearances of the various diamond cut grades using real-life examples. You will get to interact with video listings and see how they look like up-close. Head onto the next page and continue reading…