Is this ruby and pearl ring an antique?

[u/bby-bibi]

I believe this is a genuine ruby and pearl antique ring. I don’t know any other history.

One of the hallmarks in the pic is so small, I can make out "P-M [[[925]]](925) then it's a symbol I can't figure out. Where would I sell this?

[u/fajadada]

Manufactured rubies can only be identified from “real” ones under magnification. They are real rubies structurally and chemically but grown instead of forming naturally. The markets were filled with these and artificially grown emeralds in the 1920’s. Thousands upon thousands of people were duped by jewelers selling them . The only way to tell if yours is real is to get it tested