VINTAGE SILVER TONE FILIGREE SOMBRERO HAT w/Dangles-mexican silver?

This is a necklace my sister has had since the mid 70's.
I'm not sure if it's silver, there is no stamping.  But the whole thing is tarnished like silver
the "Hat" shield is 2 1/2" wide
the chain drop is 11"
no lock, just put over your head.
Thanks for looking
I combine shipping