This is a modified or combination cut - a brilliant cut square or rectangle shaped diamond with clipped-off corners like the emerald cut. It melds the elegance of the emerald cut diamond with the brilliance and sparkle of the round diamond.
This square or rectangular cut combines the elegance of the emerald shape diamond with the brilliance of the round, and its 70 facets maximize the effect of its color refraction. Because of its design, this cut requires more weight to be directed toward the diamond's depth in order to maximize brilliance. Depth percentages of 70% to 78% are not uncommon.
Length to width ratio: A radiant cut with a length to width ratio of less than or equal to 1.05:1 will appear square to the observer. While a squarer radiant-cut diamond is the preference of many, some people prefer a slightly rectangular diamond.