| 摘要 |
PCT No. PCT/GB95/01968 Sec. 371 Date May 5, 1997 Sec. 102(e) Date May 5, 1997 PCT Filed Aug. 18, 1995 PCT Pub. No. WO96/07894 PCT Pub. Date Mar. 14, 1996In order to provide a simple, safe and compact apparatus for distinguishing natural, colorless, or near-colorless diamond from synthetic diamond, the apparatus is equipped with a chamber in which a flash lamp irradiates a stationary diamond with irradiation which has a substantial component of ultra-violet light below 250 nm or 255 nm. The intensity of phosphorescence emitted by the diamond after irradiation by the lamp is measured by a photomultiplier tube which sends a signal to a microprocessor. There is a visual display of the elapsed time for the phosphorescence intensity to decrease to a threshold value. The diamond is classified as probably natural if it has no phosphorescence or a short phosphorescence time. |
