METHOD FOR PRODUCTION OF QUARTZ SINGLE CRYSTALS FOR JEWELRY Russian patent published in 1996 - IPC

FIELD: production of artificial jewelry materials, particular, quartz single crystals pressing opalescence and colored varietals. SUBSTANCE: quartz single crystals are grown by hydrothermal method from quartz mixture on obliquely sliced seed wafers which differ from basic cut (pinakoild) 0001 of crystal att angle of not less than 30 deg in alkali medium at temperature of 300-350 C and pressure of 200-300 kgf/sq.cm. After cutting crystals into blanks, their machining and polishing to produce product of desired insert shape, they are subjected to heat treatment in copper vitriol at 550-600 C for, at least, 10 h in rising and dropping temperature at the rate of within 50-100 C/h. As a result, inserts are obtained monochromatic orange, yellow, honey-colored and the like with bright (fire, flame) opalescence. EFFECT: higher efficiency.