The purity of silver lands on a numeric scale, or rating system, based on 1,000. Pure silver gets a 999 rating. In order for a silver to be classified as Sterling Silver, it must meet at least a 92.5 purity. In other words, 925 silver is Sterling Silver.
Silver jewelry is never made of Pure silver because the metal is too soft in its pure form. Therefore, we mix other metals together with the pure silver so that it will be strong enough for the normal wear and tear jewelry gets. This mix is called alloy.
Best Quality 925 Silver
However, this is where it gets interesting. The only prerequisite to get the 925 stamp is that 92.5% of the jewelry is pure silver. There are no regulations as to what the 7.5% alloy should be made up of. That means jewelry companies can get away with using 7.5% nickel or 7.5% zinc, or a mix. Apart from being cheaper metals, these are also not very strong materials, meaning the silver jewelry will break much more easily.
The best 925 silver quality is made up of 92.5% silver and 7.5% copper, because copper is a harder metal. Copper has a hardness of 6 on Moh's Hardness Scale, (versus Zinc rated at 2.5 and Nickel at 4).
You Deserve The Best Only
At Chiaro Jewelry, we only use 925 Sterling Silver of the best quality, with a pure 7.5% copper alloy.