METHOD AND MULTIPLE-PUNCH APPARATUS FOR DIAMOND DRESSING IN REACTION CELL Russian patent published in 2003 - IPC

FIELD: dressing diamonds. SUBSTANCE: method includes press-fitting diamond crystal 7 in disk- shaped backing 6 made of composition whose proportion of ingredients is as follows, mas.%: MgO, 80-85; ZrO2, 12-15; CsCL, 3-5; disk diameter does not exceed its height and exceeds size of press-fitted diamond by at least two times. Backing 6 is placed in reaction cell incorporating coaxially mounted heating element 1 with current lead-in lids 2 and current lead-in rods 4, as well as closing pellets 5; it is exposed to atmospheric pressure for 20-30 h and temperature not over 120 C whereupon it is held in hydrogen stream for 0.5-20 h at 100-200 C. After that cell is placed into multiple-punch apparatus and held therein at high pressures and temperatures for time sufficient to change color of crystal. Then pressure is released to atmospheric value while temperature is maintained within reaction cell between 900 and 1000 C. EFFECT: improved physical properties of diamonds including their color. 3 cl, 1 dwg