Home / Standards / GB/T 18303-2008 GB/T 18303-2008 Active Color grading of polished diamond by visual matching 钻石色级目视评价方法 Standard Type GBT ICS 39.060 CCS D58 Status 现行 Issue Date 2008-05-26 Implementation 2008-11-01 Responsible Dept 国家标准委 Drafting Unit 国家标准委