Abstract: A gemstone is provided and has a large surface-area, plate-shaped support having a surface with least one pyramid-shaped depression. A thin vapor phase deposit layer comprises a thin, surface-shaped precious synthetic gemstone layer disposed on the large surface-area, plate-shaped support and has an upper surface facing away from the plate-shaped support and an underside having at least one pyramid-shaped projection disposed in and coinciding with the pyramid-shaped depression of the support. Side faces of the pyramid-shaped projections of the underside of the vapor phase deposit layer upon the plate-shaped support impart decorative, diamond-light-reflective qualities to the synthetic gemstone layer.

Abstract: An abrasive body for grinding optical glass, precious and natural stones such as marble, or other material such as wood, metal, plastic or the like is provided. The abrasive body comprises a base body of woven, knitted or embroidered fabric made of carbon fibers, or of a graphite foil. A uniform, homogeneous diamond or boron nitride coating is deposited on the base body as a grinding layer.

Abstract: A gemstone has a plate-shaped support having a surface with at least one pyramid-shaped depression. A precious stone layer is produced by vapor phase deposition on the plate-shaped support. The precious stone layer can be cut.