.925 Sterling Silver is a metal made of pure silver alloy of about 92% in weight of silver and about 8% in weight of copper metal. its minimum fineness is about 925.
Sterling silver is soft so its mainly alloyed with copper metal to give it some degree of hardness and toughness wit withstand sever conditions.
Technically, sterling silver rings tend to last more than gold plated rings because sterling silver rings do not turn brown when it starts tarnishing after a long time, rather it becomes dull in brightness than how it was initially. As most wedding bands comes in sterling silver, and from a broad survey, sterling silver has been the most beautiful amongst all metals used in rings.