Abstract: In accordance with the requirements of the national standard, a better instrument and method for diamond color grading has been developed, and the effect is very small by the detection of environmental conditions, personnel and sample size. This method is used to test the different standard stones, and the results show that the color uniformity is not ideal. So the conception of diamond quantization color gradation system is put forward, which makes the diamond grading quantitative. so that the diamond grading is really unified to a standard. The idea can unify the global diamond grading standards, make the diamond grading technology more scientific, fair and reasonable.

Key words: In accordance with the requirements of the national standard, a better instrument and method for diamond color grading has been developed, and the effect is very small by the detection of environmental conditions, personnel and sample size. This method is used to test the different standard stones, and the results show that the color uniformity is not ideal. So the conception of diamond quantization color gradation system is put forward, which makes the diamond grading quantitative. so that the diamond grading is really unified to a standard. The idea can unify the global diamond grading standards, make the diamond grading technology more scientific, fair and reasonable.