Diamond is cut in the shape of a rectangle with trimmed corners. Radiant cut diamonds facets are cut into a pattern that gives this diamond the unique appearance of cracked ice. Radiant cut diamonds can vary in their degree of rectangularity.
 

For a square radiant, look for a length to width ratio between 1.00 and 1.10. For a rectangular radiant, the length to width ratio should be between 1.50 and 2.00. Regardless of how rectangular the radiant is, the table should be between 65 - 80% and depth between 65 - 75%.