Brilliant (Round): Provides the most fire and scintillation among the different grades of diamond and gems, making this shape popular for use with widely varying grades of quality stones. The round cut has been thoroughly researched for over a century with precise mathematical calculations to provide the most optimum amount of brilliance. The round brilliant cut is actually an adaptation of the emerald cut, which, unlike the emerald cut, uses brilliant facets instead of steps. These calculations were pioneered before the turn of the 20th century by Russian Mathematician, Marcel Tolkowsky, who gave the specifications that were necessary to acheive this maximum brilliance and scintillation. He specified that the cut height for a round shape be 59.3% of the diameter of the diamond. Tolkowsky further broke down the proportions to be 43% of the pavilion and 16% for the height of the crown. He also specified 57 facets, not including the culet (bottom point). This discovery marked a biginning of a revolution in cuts, which would be followed by many adaptations into many of the modern shapes we know today, like marquise, oval, and pear. This also marked the beginning of facet designs that would emit as much light, fire, and scintillation as possible, unlike earlier cuts such as the emerald, asscher, and cushion, which absorbed light, providing the eye with beautiful clarity and depth, similar to a pool of water.