Sterling silver is an excellent alloy of silver with 92.5 percent pure silver and merely 7.5 percent other metals like copper. This silver hardly turns. However, lower-grade versions of the silver may tarnish after some time. These may react with dirt and similar oils, leading to a chemical process or oxidation.
Although, there are various ways to ensure that your silver jewelry doesn\'t tarnish and hence use vinegar to attain the best results.