There are three broad categories of lapidary arts&colon; tumbling, cabochon cutting, and faceting. Diamond cutters use this attribute to cleave some stones, prior to faceting. Masters of diamond and gem faceting began appearing. The art of cutting a gem is an exacting procedure performed on a faceting machine. Spheres are simulated with cubic, octahedral, and tetrahedral faceting. In 3D these include&colon; stellation, faceting, augmentation, excavation, drilling and dualising. Today, Smolensk is noted for its electronics, textiles, food processing, and diamond faceting industries. A bcc crystal is achieved by faceting a sphere octahedrally. The reciprocal process to stellation is called facetting (or faceting). This technique can produce many unusual and artistic variations of the traditional faceting process. It can be seen as a faceting of a regular dodecahedron. The dopstick can be hand-held or inserted into the indexing equipment for more precise faceting. It is a faceting of a dodecahedron, as shown at left. The particular faceting amount determines the lattice that assembles. Abfraction, faceting and possible vertical enamel fracture lesions should also be noted if present.