Necklace with odd marking

[billjustbill]

Got a twisted rope necklace mixed in a junk bag. It's marked "Str-P". I can't seem to find what this marking means, and so I can't tell anything of its value.

Do you know what the marking means?

Thanks

 

[tamrock]

"Str-p"... Sterling Plated? scratch a spot and do an acid test and if you feel like it post a picture.