If you aren’t in the market for a round diamond and want to buy a fancy shape diamond instead, you better be prepared for a tougher selection process. There are 2 main reasons that make fancies harder to choose. Firstly, unlike the popular round diamonds which can be found in almost every jewelry store, fancy cuts aren’t high in demand. That means that stores typically don’t hold a wide selection of stones for them.
Secondly, there is a lack of objective cut information presented in grading reports. Most gemological labs do not assign any cut grades to the fancy shapes (with the exception of AGS for top-of-the line princess and cushion cuts) and this makes it extremely difficult for consumers to determine cut quality.
Compare the GIA Dossier Reports for Round Brilliants (Left) and Fancy Shapes (Right).
Did you notice the absence of a cut grade in the report for the fancy shaped diamond? Can you also see that that the measurements for crown and pavilion angles (indicated by red arrow) are missing? Using only the limited data on cut proportions, physical dimension measurements and carat weight, it is impossible to tell how the diamond would look like in real life.
However, as a general guideline to help you narrow down your initial selections, you can use the tables of recommended proportions for the various shapes as a reference. These tables can be found in the corresponding sections of each diamond shape.
For online shoppers, having a magnified image or video to help you visualize the stone’s appearance is a MUST. The same goes for people who intend to make a purchase in a local store. Make sure you perform an inspection with a loupe and check the outline of the diamond.
Once you are done filtering down your selections, the next most important step is to obtain an ASET image. This will help you determine the optical characteristics and performance of the diamond.
The ASET tool was developed by the American Gem Society and works in a similar fashion as the ideal scope. It is used to demonstrate how a diamond handles and returns light to the observer by using colored bands of red, green, and blue. The great thing is that it also exists as a handheld tool and can be conveniently carried around.
The main difference between an ASET and Idealscope lies in how the light performance data is being presented. In terms of practical usage, the ASET is predominantly used to determine optical performances for fancy shaped diamonds whereas the IdealScope is utilized for round brilliants.
Red – Light Return Blue – Adds Contrast Green – Light From Environment White – Light Leakage
Click here to download a pdf file for the tutorial on the Angular Spectrum Evaluation Tool
To see more examples and reference charts for various diamond shapes, click this link.
Like the scenarios faced when shopping for round cut diamonds, most local brick and mortar shops do not provide any ASET data or possess an in-house setup that customers to use. To begin with, you can count yourself super lucky to find a store that can offer 2-3 choices of a particular fancy shape with the right carat weight, color and clarity grading.
To put things in perspective, let’s say I’m searching for a 1 carat cushion cut diamond with a color grade between F-H and a clarity of VVS1-SI1. A simple search on James Allen can reveal around 200-300 diamonds to choose from. Can your local shop beat that? Even with that huge amount of possible choices, I sometimes can’t even find a single diamond that meets my standards for cut quality and optical performance.
Ok, let’s say it is your lucky day and the planets happened to aligned together when you make your trip to the local store. Having 2-3 diamonds available to pick from doesn’t mean anything much. The truth is, the majority of fancy shapes are cut to optimize carat weight instead of brilliance. It is very possible that all 2-3 diamonds available are all of a lower cut quality. So,this means that you’ll only be making a choice for the “best looking” stone among badly cut diamonds.
For this reason, I advise you to work with jewelers (both online or offline) who can provide you with the required ASET data and an impartial analysis for their inventory. Unless you have a trained eye and know what kind of brilliance and patterns to look out for, shopping without any light performance data is risky.
The handheld version of the ASET scope a simple and portable device that you can carry around. However, the limitations of the device lies in getting a consistent source of lighting when examining diamonds. Having said that, you don’t have to worry about learning how to use the ASET tool if you don’t want to.
Photographs Courtesy of White Flash Inc.
At the end of the day, if you are more comfortable about shopping in a physical store, the other alternative is to invest in your own scope and bring it along with you when viewing diamonds.
Please feel free to contact me if you need a second opinion on your diamond’s ASET or Idealscope data. I do have the necessary experience in correlating light performance to ASET data and can offer you an interpretation for your image.
* Update: Due to popular reader requests, I decided to write a separate post detailing the step by step process of choosing a fancy cut diamond, click here to read it.
And now that we had dealt with the more techy stuff, we are going to touch on some other important shopping tips on the following pages…