Cushion cut diamonds, also referred to as the mine cut or old mine cut, derive their name from the shape, which resembles a pillow. What is a cushion cut diamond exactly? These loose diamonds are square or rectangular in shape, but unlike the princess cut diamond, their corners are rounded. Although generally less brilliant than round brilliant diamonds, cushions have more fire. Whether it’s this fire or their distinctive soft, rounded corners with a square shape that attracts buyers, the cushion cut has successfully claimed its spot as the third most popular diamond shape. (You can find out more about all the other diamond shapes here.) But if you plan to shop for one of these popular stones, you’ll need to know your way around their different styles and their ratios. We’ll break down traditional cuts, which have fewer but larger facets, and modern cushions or modified cushion brilliants, which have as many or more facets as a round brilliant, so you can focus on one thing: how to get the best cushion cut diamond possible.