Tibetan silver is similar to pewter. It is an alloy of copper and tin. Its overall appearance is of aged silver.
925 Sterling silver is an alloy of silver, containing 92.5% by mass of silver and 7.5% by mass of other metals, usually copper. The sterling silver standard has a minimum millesimal fineness of 925.
STS - Means 925 Sterling Silver
SP - Means silver plated - nickel and lead free GP - Means Gold plated - nickel and lead free BZ - Means Bronze Colour - nickel and lead free