What does B18K mean on a bracelet?

B18K on a bracelet indicates that the piece is made of 18-karat gold. The "B" typically signifies that the gold has been alloyed with other metals, which can enhance durability and alter color. In this context, "18K" means the gold content is 75%, with the remaining 25% made up of other metals. This hallmark assures buyers of the quality and composition of the gold used in the bracelet.