Shuibeijin is a material made by mixing gold with other alloying elements and refining. In this process, in order to increase hardness, change color or adjust other characteristics, a small amount of other metal or nonmetal elements will be added. Therefore, the purity of gold in shellfish may be lower than 999 (99.9%).
However, this does not mean that the quality of water shell gold is not good or not worth buying. On the contrary, due to the addition of other elements, Shuibeijin may have better hardness and durability and is more suitable for making jewelry.