Question: I was searching for a cushion cut diamond via an online vendor and I noticed that “cut grades” were assigned to fancy cut diamonds in their inventory.
It perplexes me because some diamonds that fall within your recommended ideal proportions were actually graded “very good” whereas another seemingly similar diamond was graded as “excellent”.
When I looked at another vendor, the same thing happens. It seems like different vendors assign different cut grades to the fancy shapes. Are these diamonds given an objective evaluation by a gemologist or do they actually follow some standards in which the grades were assigned?
Answer: Hello there, thanks for writing in. When online vendors list their diamonds for sale, the stones are actually filtered and organized based on the individual vendor’s own set of standards. For example, one vendor might assign an Excellent cut grade to a princess diamond with 71% depth and 67% table while another vendor might assign a Very Good cut grade to the same diamond.
Next, the numbers and proportion charts found on our website are just guidelines we think nice looking fancies might fall in. There are really no hard and fast rules when it comes to selecting fancies. As we had mentioned in the tables, they are there merely to act as guidelines to help you out. And the truth is, we can’t place a figure to correlate a fancy’s visual beauty based on the table and depth proportions only.
Besides that, the polish and symmetry grading of a fancy is really unrelated to how the diamond will look in real life. Very often, you will find that a Very Good/Good diamond can look a lot better than another diamond with Excellent/Excellent polish and symmetry.
When buying fancies, the best way would be to see the stones in person. However, this is not a luxury many people can enjoy because most local jewelers don’t carry enough of them for you to cherry pick and to make good comparisons.
The next best option for you is to work with vendors who can help you take an ASET image of your shortlisted diamond. This ASET photograph can help you “determine” the diamond’s light performance and enables you to infer how it looks like in real life.
ASET images will reveal the diamond’s light performance
As you can see, the cushion cut diamond on the right has better light performance than the one on the left. This translates to more sparkle and brightness in the stone. Without seeing the diamond in person or ASET (for online purchases), there is no way to tell the differences in optics between them.