4800 Pcs Jump Rings for Jewelry Making, Silver and Gold Open Jump Rings for Keychains Earrings Necklaces Bracelets Charms Repair, 5 Sizes Jump Hoops (4/5/6/8/10mm)

Q: Does anyone know exactly what kind of metal these are made of? Do they contain nickel? Will they turn your skin green if you wear them for awhile?

This open Jump Ring sets is made of upgraded iron materials, they are jewelry special iron, no lead and nickel, with hypoallergenic, also will not appear as you say make the skin green, please feel free to use! I hope the above answer is helpful to you, best wishes!