| 摘要 |
PURPOSE:To accomplish uniform coloring into the depth of diamond by heat treatment of diamond irradiated with electron beams while cooling in water. CONSTITUTION:A diamond is immersed in water and irradiated with electron beams of >=2MeV (pref. >=10MeV) for 5min-2hr so as to result in 10<8>-10<11>rad to effect coloring blue. Thence, the resultant diamond is heat-treated under the atmospheric pressure either at 300-400 deg.C for 5min-1hr to fade the blue color thereof and increase its brightness, or at 400-600 deg.C for 5min-1hr to effect color change to blue green - green and increase its brightness, or at 600-800 deg.C for 5min 1hr to effect color change to lemon yellow - gold and increase its brightness. |
