Vintage Pearls Pearl Earrings With 4k And S Shape On French Back What Is This?

Pearl Earrings with 4k and S shape on french back What is this? - vintage pearls

I bought a set of antique pearl earrings. You have 4k support in French and S, and engraved on the back. (I think the S) is a registered trademark Who knows what that means? How much should I pay for two roses in circulation? I think they are pearls of age.