Brass

Brass is an alloy of copper and zinc, in proportions which can be varied to achieve varying mechanical, electrical, and chemical properties.^[1] It is a substitutional alloy: atoms of the two constituents may replace each other within the same crystal structure. The composition of brass, generally 66% copper and 34% zinc, makes it a favorable substitute for copper based jewelry, as it exhibits greater resistance to corrosion.

https://en.wikipedia.org/wiki/Brass