(n) Repeating groups of polygons of similar topology, forming an approximate representation of a curved surface. Curved surfaces such as cylinders and spheres are subdivided into a series of faceted planar surfaces, which approximate the original surface. This transformation is often used so that curved surfaces can be rendered using algorithms that only support planar surfaces.
The flat-faced angles that are cut into a diamond in order to maximize it's fire and brilliance.
A facet is the ground area on the blade that creates the cutting edge. Also referred to as a "bevel." Grind facet - ground bevel placed on blade first using a coarse grit wheel at a relatively low angle in an effort to remove most of the stock prior to honing. Hone facet - a smaller ground bevel added after the grind facet at a somewhat higher angle to assure the minimum amount of stock removal and the best possible finish using a finer grit grinding wheel.
These are tiny surfaces polished onto a rough stone that lend a finished diamond its shape. The way light interacts with these facets generates a diamond's brilliance and sparkle.