999 silver jewelry is the closest you'll get to pure silver. It's called . 999 silver because it's technically 99.9% pure silver! This type of silver is the highest quality silver you can buy.925 Sterling silver contains 92.5% pure silver which is mixed with some sort of alloy material such as copper. ... Because silver is a soft metal, this coating can be scratched off and tarnished easily, eventually exposing the metal or alloy underneath when the coating is removed.05-Nov-2015 There is no difference between silver that is labeled as s925 or 925 — both of these stamps designate that piece of jewelry as high-quality sterling silver. You may also see sterling silver stamped with things like “sterling,” “ss” or “ster,” which can also be used to indicate they meet that 92.5% purity standard.