Radiant cut diamonds combine the sophisticated shape and elegance of emerald cut diamonds with the brilliance of round cut diamonds. It used to be that square or rectangular shaped diamonds had a glassy appearance due to the way the stone was cut. This "step cut" has broader lines which can appear flat, making it difficult to reflect light as well as the brilliant cut diamonds.
However, with radiant cut diamonds, you get the best of both worlds. If you love the look of the emerald cut diamond, but feel that it is just too lackluster, than you will fall in love with the radiant cut. 70 facets offer brilliant light refraction, which is what makes the diamond sparkle in the light.
To find the dimension of radiant you want, look for the length-to-width ratio on each diamond's detail page. This will determine what the diamond will look like when viewing it from above.
For a radiant diamond shape that is square, look for length-to-width ratios between 1 and 1.07. If you prefer more of a rectangular shape, look for length-to-width ratios greater than 1.07.