As previously noted, sterling silver is an alloy consisting of 92.5% silver, while the remaining 7.5% of its composition is made of copper and other metals. On the other hand, pure silver has an actual silver content of 99.9%. Due to this high purity, fine silver is usually too soft for use in making jewelry and other antiques, which is why it is mixed with other metals.
If you think you may have a pure – or fine – silver antique, you can look for its distinctive markings. Fine silver is usually stamped with marks like “.999,” “999,” or “99.9.”