Emerald cut diamonds are cut with rectangular facets to create a unique optical appearance. Due to its larger, open table, this shape highlights the clarity of a diamond. If you choose an emerald cut with a lower clarity grade, such as SI, be sure to review the clarity plot on the diamond certificate. Also, emerald cut diamonds can vary greatly in how rectangular they are. If you would prefer an emerald cut with a squared outline, look for an Asscher cut diamond. The length-to-width ratio will determine the diamond's outline, or what it will look like when viewed from the top.

For the classic emerald cut shape, look for a length-to-width ratio between 1.30 and 1.40.