The method by which a rough diamond that has been mined from the earth is shaped into a finished, faceted stone. As a first step, cleaving or sawing is often used to separate the rough into smaller, more workable pieces that will each eventually become an individual polished gem. Next, bruiting grinds away the edges, providing the outline shape (for example, heart, oval or round) for the gem. Faceting is done in two steps: during blocking, the table, culet, bezel and pavilion main facets are cut; afterward, the star, upper girdle and lower girdle facets are added. Once the fully faceted diamond has been inspected and improved, it is boiled in hydrochloric and sulfuric acids to remove dust and oil. The diamond is then considered a finished, polished gem.
Diamond Cutting is the art, skill and, increasingly, science of changing a diamond from a rough stone into an attractive gem. It is possible only because the hardness of diamond varies widely according to the direction in which one is trying to cut or grind.