I was given this brooch years ago and thought it was costume jewelry until recently. It is not my style of jewelry so I never wore it. My gem tester reads ruby for both gems. The signature is scratched into the back. I doubt it is a significant artist since it is not engraved. I cannot guarantee these are rubies, only report they appear to be so based on my findings. I am not a jeweler I am someone with a lot of jewelry and experience but not the expertise to determine for sure what these are. The piece is heavy and solid. It has sat for at least 15 years in the bottom of a jewelry box. If you like the Brutalist movement, solid silver pieces or rubies, give it a good home.