Hi,
All of our clasps and wire are made of sterling silver. We can also do gold-filled by request. I also have a nickel sensitivity and can't wear cheap jewelry myself so I'm very conscious of what we use.
Sterling silver is 92.5% silver and 7.5% is made up of another alloy. Almost all sterling silver made today uses copper as the second alloy. Years ago they used to use nickel as the second alloy which is why many people think they are allergic to silver even though they are most likely allergic to nickel. All the silver that I use is 92.5% silver with 7.5% copper.
Gold-filled is made by using heat and pressure to apply a layer of karat gold to a base of another metal usually brass or sterling silver. This produces a surface with karat gold. The minimum layer of karat gold must equal at least 1/20 of the total weight of the item. Tubing is usually seamless, so that only gold touches the body. Most gold-filled that we use is 14K 1/20 gold-filled.
Anyway, this is more info than what you asked for but I thought I would share some of my research.
Thanks for your question.
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