1. Every region generally has a gold and jewelry appraisal center. Generally, it is the Golden Pearl Bao Hui Quality Inspection Center of Tanzhou Institute of Quality and Technical Supervision and Inspection, the Gold Jewelry Quality Inspection Center of Ansai Institute of Quality and Technical Supervision and Inspection, or the Jewelry and Jade Appraisal Center. 2. All major gold shops, usually small-scale gold shops, have gold appraisal services. Pure stone: 1, color identification method: According to the different luster and color of gold, pure gold, k gold, real gold and fake gold can be roughly distinguished. Red gold is the best, with a fineness of over 95%; The fineness of positive yellow is about 80%; Cyan accounts for about 70%; Yellow is light gray, and the fineness is about 50%. Folk call it "seven green, eight yellow, nine five red, yellow and white with gray and half gold." If it is a gold jewelry that has been stored for a long time, there is a saying that "copper turns green, silver turns black, and gold never changes color". Therefore, the more positive the color of gold, the higher the purity. 2, timbre identification method: listen to the rhyme to see the elasticity. When high-quality gold jewelry is knocked or thrown to the hard ground, it will make a hearty hum of "poof-poof-poof", which is disorganized and inelastic. K gold has rhyme, sound and elasticity. The greater the elasticity, the older the rhyme and the worse the color. Therefore, the higher the purity of gold, the smaller the elasticity and the smaller the sound.