【国家标准】 钻石分级

This standard specifies the terms and definitions of natural unmounted and mounted polished diamonds, diamond color, clarity, cut grading rules, diamond weight and diamond grading report.
This standard is applicable to diamond grading and related activities in the fields of gems testing, cultural relics testing, commerce and trade, customs, insurance, pawn, asset evaluation, scientific research teaching, and literature publishing.
The color grading in this standard is applicable to unmounted and mounted polished diamonds in the color series ranging from colorless to pale yellow (brown, gray).
The cut grading in this standard is applicable to unmounted and mounted polished diamonds of round brilliant cut.
The grading rules in this standard are applicable to unmounted and mounted polished diamonds that have not been treated by coating,filling, etc.
The grading rules in this standard are applicable to unmounted polished diamonds with a weight of 0.040 0 g(0.2