Round
The round brilliant cut diamond is by far the most popular and most researched diamond shape available today. For almost 100 years, diamond cutters have been using advanced theories of light behavior and precise mathematical calculations to optimize the fire and brilliance in a round diamond. In addition to being the most popular and researched shape, a round diamond will typically give you more flexibility in terms of balancing cut, color, and clarity grades while still getting the fire and brilliance you want.
To maximize the brilliance of a traditional round diamond, select one in the two highest cut grades, ideal or very good, and choose ideal, excellent, or very good polish and symmetry grades. For the finest ideal round diamonds available, view the Blue Nile Signature Round Collection.
Princess
This is our most popular non-round diamond. Its beautiful brilliance and unique cut makes it a favorite for engagement rings. The princess has pointed corners and is traditionally square in shape. When choosing a color grade, consider that while the price of a J-color non-round diamond is exceptional, color may be slightly visible in its corners. Also, princess-cut diamonds can vary greatly in how square or rectangular they are. To find the dimension of princess you want, look for the length-to-width ratio in our interactive diamond search and on each diamond's detail page. This will determine what the diamond will look like when viewing it from above. Here are length-to-width ratios for princess-cut diamond shapes that are pleasing to the eye.