METHOD FOR OBTAINING GEM STONES Russian patent published in 2023 - IPC A44C17/00 C30B23/06 C30B29/36 

FIELD: jewellery industry.

SUBSTANCE: invention can be used in the manufacture of inserts in jewellery that imitate diamond. Single-crystalline silicon carbide is grown by sublimation onto a seed crystal located in the reaction chamber on a substrate-tape, for example a SiC single crystal of the 4H, 6H or 3C polytype. The inner wall of the reaction chamber, at least part of which is made of silicon carbide, is heated to 2100-2300°C. The reaction chamber is evacuated, adjusting the air pressure in it in the range of 1000-10000 Pa. Silicon carbide in a liquid state is supplied to the surface of the substrate-tape, while simultaneously moving the substrate-tape in a horizontal plane at a speed of 0.2-2.0 m/min. The grown crystals are separated into individual crystals, cut and polished into a finished gemstone. Cutting can be carried out on abrasive disks with a grain size from 20 to 100 microns or on grinding discs with an abrasive grain size from 3 to 10 microns. The surfaces of the edges are polished using fine-grained abrasive materials with a grain size of 0.125-0.45 microns. The resulting silicon carbide single crystals have jewellery quality, high shine, clear edges and are resistant to external influences.

EFFECT: high productivity due to the elimination of crystal cutting operations.

7 cl