Stamped! Vintage Louis C Marks designed for the Rice-Weiner company during the 1940s. It was hard to find info on his personal lines of jewelry but I’m guessing if you do some digging it will be interesting! Clasp is a little loose but will stay out if you don’t mess with it while on. There are extenders as well attached but I find I need to wear it as a choker for the necklace to lay flat against my neck. It’s a very original piece!