The cut in gemstones is also of great importance. Generally there are two types of cuts — commercial
. The main objective in first one is to preserve as much as possible of the crystal’s size, respectively weight, while the second follows exact proportions, angles, etc., always in relation with the specific mineral.
During the cutting process the gemstone is given a different form, which may be with curved surface, as in cabochon
type, or consisting of facets. Huge database of various faceting diagrams exists on FacetDiagrams.org