When I was searching for an emerald cut diamond to make Jennifer’s engagement ring, I looked at many different emerald cut diamonds, all with different proportions, color and clarity grades. Here’s a helpful guideline on what to look for:
First thing that you’ll notice, when you compare emerald cut diamonds, is their overall shape. There are narrow emerald cuts, perfect rectangular emerald cuts and more square looking emerald cut diamonds. The perfect rectangular emerald cut has a length to width ratio of 1.4. Above 1.5 ratio, the diamond starts looking narrow and it may not show its weight. Below 1.4 ratio, the diamond starts looking more square. The 3.64 carat emerald cut diamond in Jennifer’s engagement ring has measurements of 10.18 x 7.23 x 5.15 millimeters. When you divide it’s length 10.18 by its width 7.23, you get exactly 1.4.
Emerald cut diamonds don’t show color the way round brilliant cuts do. A G-H color emerald cut diamond is very desirable. If you have to compromise, you can even go to I color.
Emerald cut diamonds will show inclusions easily. While an SI1 clarity is a good compromise for other diamond shapes, for an emerald cut, VS2 would be a comparable choice.
These guidelines for ratios, color and clarity for emerald cut diamonds are set by GIA. Beauty is subjective, but it always helps to compare. Below is a diagram comparing the length to width ratios of three different emerald cut diamonds.