Necklace engraved with a J and crown?

Hi! I was recently given a piece of jewelry that has a trademark I’ve never seen. Just curious if anyone may know who makes this jewelry? It’s a very nice silver piece that has the letter J with a crown above it on the clasp. There’s also another little charm on the opposite end with just a crown etched in the silver. I’m tried searching online with no such luck. Any ideas, or anyone come across this before? Thank you!