Thousands of gold with a gold content of not less than 999 is called thousands of gold, which is the highest value in jewelry color naming. The stamps are thousands of gold, 999 gold, 999 gold or g999 gold. The imprint of gold jewelry includes manufacturer's code, material and purity, such as X Gold 990, XAu990 and X Pure Gold. Where the letter X is the manufacturer's code. When jewelry is made of precious metals with different materials or purities, the materials and purities should be indicated separately. When jewelry is too thin or too small to print, it should be accompanied by a logo containing the contents of the imprint.
On the eve of the Spring Festival of 20 15, the National Standardization Administration Committee published the revision of GB 1187-2012 "Provisions and Naming Methods of Precious Metals in Jewelry", which took effect on May 4, 2000/6. In the future, even gold with a purity of 999.0‰