Necklaces and pendants sold by regular jewelry merchants are marked. For example, a gold necklace and pendant with 1 main diamond weight of 0.23ct and platinum purity of Pt900 should be marked with the words "KNZO, PT900, 1D-0.230ct". If it is 18K gold-set ruby necklace and pendant, the main stone weight is 1.26ct, and the words "18K (or G750 or Au750), 1R- 1.260ct" should be marked. According to these signs, consumers can identify them by comparing them with commodity price tags and inspection certificates. Learn this, and go to a regular merchant to buy the jewelry necklace and pendant that you have long wanted.