Most cheap and even some more expensive gold plated faucets will have a plastic or varnished coating / masking to protect the gold from scratching when cleaning chemicals or scouring powders are used.
Try waving a torch flame over it and see if it melts this coating before going to the striping cell., or look very close around the edges of the faucet for chipping or peeling. If it is coated, you will need to incinerate first.
I have scraped allot of faucets in the last 40 years and I don't think I have ever run into any aluminum.
In most cases if its metal at all it will be zinc / die-cast , brass or stainless for the parts that show or take the plating.
If it's a really cheap faucet ( feather lite ) it may be plastic, care full the torch don't set it on fire.
Ray
PS: If it's from China it could be asbestos impregnated plastic with a lead based paint - look out :lol:
Ok silly me