Vintage St. Christopher Metal Pendant with Nice Patina

Vintage St. Christopher metal pendant. The metal is unknown, but this piece has a thick and grungy patina like sterling does. It has no marks. I don't want to disturb the patina to acid test it.  The patina is black. Just beautiful. Needs a jump ring. Measures 1 3/8" tall by 5/8" wide. Weight: 5.1 grams.