In tiffany sterling silver is copper! But I'm allergic to nickel so is nickel in copper?
Nickel is not alloyed with copper for any sort of jewelry purposes. Nickel is alloyed with gold and silver to make white gold
Sterling silver is 925 fine or 92.5% silver, and usually 7.5% copper. Other metals may replace copper to improve porosity, viscosity, etc. They are platinum, zinc or germanium, not nickel.
Nickel, silver and copper are three distinct and different metallic elements. Nickel and copper do occur together in some ores (such as Sudbury and Kambalda) and may include some silver, but they are all different elements. You'd have to know the composition of the alloy used in your jewelry.
