copper wire

[danny1987]

Is copper wire usually pure copper, or is it alloyed?

 

[pygmy]

Is allways pure and if shiny ( not burnt or corroded ) fetches best price. Unless yo color blind is simple to tell if Cu pure.
Maybe u mean a coating --sometimes a silvery coating thats tin ( solders better) or a lacquer/ resin in transformers/motor windings for insulation. This obviously reduces price as no longer pure.