METHOD OF GROWING CRYSTALS OF QUARTZ OR AMETHYST OR AMETHYST DRUSES BY A HYDROTHERMAL METHOD OF TEMPERATURE DROP IN AQUEOUS SOLUTIONS OF AMMONIUM FLUORIDE Russian patent published in 2019 - IPC C30B7/10 C30B28/04 C30B29/18 A44C17/00 

FIELD: chemistry.

SUBSTANCE: invention relates to production of quartz mono- and polycrystals for synthesis of optical and piezoelectric monocrystals of quartz, including those doped with germanium, for radioelectronic, optoelectronic and acoustoelectronic equipment, and for production of colored monocrystals and druses for use in stone cutting and jewelery. Crystal growing of quartz or amethyst or amethyst druses is carried out by hydrothermal method of temperature drop in aqueous solutions of ammonium fluoride on seeds, at that, potassium fluoride in amount of 10–40 g per liter of water solution of ammonium fluoride is additionally added to initial solution. Growth of monocrystals of colorless quartz is carried out on monocrystalline quartz primers parallel to faces of trigonal prism x{11-20} and trigonal pyramid s{11-21}. Growth of amethyst monocrystals is carried out on monocrystalline quartz primers parallel to the vertex of trigonal pyramid s{11-21}. Cultivation of amethyst druses is carried out on seeds of polycrystalline quartz with isolated aggregates of different crystallographic direction cut out of natural vein quartz.

EFFECT: due to use of solutions of ammonium fluoride with addition of potassium fluoride it is possible to reduce duration of growing process till 2–3 months due to increase of growth rate of crystals in 2–3,5 times at simultaneous preservation of their high quality.

7 cl, 1 tbl, 14 ex