Vintage Hersheys kiss birthstone necklace May green glass stone enduring kiss

Beautiful silver necklace, stamped on bottom enduring kiss, I'm not sure if this is sterling silver or not I think it's plated, it's in excellent condition no loss of silver on this! This is a birthstone necklace it had a emerald green glass stone. chain looks good too. 18" long. The kiss is smooth not textured. box 15