Vermeil is any piece of jewelry that consists of a sterling silver base layer, with a solid gold layer electroplated on top.
However, for a piece of jewelry to be marketed as "gold vermeil" in the United States, it must meet specific requirements:
- The base material must be sterling silver. Sterling silver is an alloy containing 92.5% by weight of silver and 7.5% by other metals, which is usually copper. The alloy is harder than fine silver (or pure silver), but it is prone to tarnishing. Its conductive surface makes it a good base for plating, as with vermeil.
- The gold-plated layer must be comprised of at least 10 karat gold, but it can range from 14k to 24k.
- The sterling silver must be plated in gold at least 2.5 microns thick (micron = 1/1000th of a millimeter)