This is a vintage antique gold tone or most likely brass (with aged, rich, mellow patina) necklace. The necklace has a layered, filigree, richly detailed, domed pendant.This pendant has many sapphire blue colored glass rhinestones with a gorgeous blue givre stone (prong set) showcased at its center. This stone is made of glass and is unfoiled and in an open back setting. Also, it is most likely that this piece came from West Germany but I can find no markings. Possibly, the clasp ring has been replaced? Or maybe it was on earrings and not the necklace?