Could this item be silver it will not attract a magnet it is an original item

A german metal police emblem for a motercycle

Nickel, cobalt and iron are the only metals that will attract a magnet. Silver is not one of them.

Tick

As tickle said, nickel, cobalt and iron (and alloys of iron, e.g. steel) are the only magnetic metals.

Therefore this item could be silver, copper, aluminium... or any other metal.

Ferrous materials are Magnetic, non ferrous are not.
I think pewter is not magnetic as well. Good stainless is not magnetic.
Cheap stainless may be magnetic and may rust.
What Bike?