Generally, it is the brand of jewelry, and then the material description is needed. For example, Pt990 refers to platinum jewelry with a platinum content of 990%, Pt950 refers to jewelry with a platinum content of 95%, and the remaining 5% is other precious metals. S925 is the symbol of silver content in silver products. 925 silver is jewelry made of raw silver with a silver content of 92.5%, and Au750 refers to jewelry with a gold and silver content of 75%.