just use some wadding on it. you will soon tell if its aluminium if it shines up within about 2 mins of rubbing it
if its steel it will require a lot of wet n dry paper work to get it polished... shich is pointless as it will just rust over soon after 
Mild steel= Magnetic and rusts
Crap Stainless = Slightly magnetic (Feritic) and rusts slowly on surface
Good stainless= non magnetic and will not rust (cracks)
there are otherways to test stainless but i cant be bothered to type all night

Aluminium would melt/crack and fall off so it aint that

Is it a silencer or just meant to look like a cat?
