Sterling silver is an alloy of silver containing 92.5 % by weight of silver and 7.5 % by weight of other metals, usually copper.
What ist gold-filled ?
Gold-filled jewelry is jewelry composed of a solid layer of gold, mechanically bonded to a base of either sterling silver or some base metal. Most high quality gold-filled pieces have the same appearance as high carat gold. It is layed with 50 to 100 times more gold than than by regular gold plating.