I would put this into the 50s--somewhere, not quite sure where! Those beaded cluster pieces (I have or had earrings almost identical and have had many similar pair) were popular into the early 60s, I think, but the chain, clasp, and backing disk on your choker look earlier than that (at least to me, but I'm not by any means a jewelry expert). I'll play it safe and guess mid 50s. Is there a maker's mark on the back of the clasp?