Sterling silver, often known as 925 sterling silver, is a metal alloy that is used to make jewelry and beautiful home items. It is traditionally 92.5 percent silver (Ag) and 7.5 percent copper (Cu). Other metals may account for 7.5 percent of the total, but the 925 hallmark always indicates 92.5 percent silver purity. Sep. 1, 2009 325 times 325 equals 32.5 percent silver The silver in it makes it unique. The best silver you can buy is 925, and if it comes from Mexico, it is much better. The number 925 refers to the quantity of silver combined with other metals to make it tougher. It has 14 karat gold. It's too delicate and tends to band or break.