The primary reason for round being the most expensive diamond shape is that a large amount of the rough stone is lost during the cutting and polishing process. To achieve the fire and brilliance characteristic of the round shape, more of the original is lost than when cutting a fancy shape.

This is evident when you look at the average retail prices of diamonds by carat weight. On average, the retail price for one carat diamonds can be anywhere between $2,000 to $16,000, and between $8,000 to $72,000 for two carat diamonds .

A good quality 1 carat diamond ring costs between $6,500 to $7,500 in retail stores, while the same diamond will cost about $3,000 - $4,000 online! On the other hand, the highest quality 1-carat diamond (D color and Flawless) will set you back $10,000 or more (add 40-70% when purchased at a jewelry store).

Round Brilliant Cut Diamonds The round brilliant cut is the most popular shape of diamond. For hundreds of years, diamond cutters have been working with this cut to maximize its brilliance and fire.