What is a round cut diamond?

A round cut diamond is a circular-shaped stone cut with 57 facets, engineered to maximize light return through the crown and pavilion. This configuration, called the round brilliant, accounts for roughly 75% of all diamonds sold globally, making it the dominant cut across both lab-grown and mined categories. The geometry is precise: each facet angle is calculated to redirect light upward rather than letting it escape through the sides or base. For lab-grown diamonds, the round brilliant is particularly well-suited because IGI grading reports assess cut quality with the same criteria applied to any brilliant-cut stone.