Art Deco best Diamond Pendant

Product Name: Art Deco best Diamond Pendant
I purchased this vintage piece wear to a historical event at The Grand Hotel, but the event was cancelled during COVID. The clasp does not close properly, so a jeweler will need to slightly adjust to ensure proper closure. The chain measures 15" best and the pendant is 11/2" including the bail. Diamonds are clear and sparkly. The top diamond is bezel set & the bottom one is prong set. I would estimate the top diamond to be about .05 points and the bottom to be about .18 pt. Was sold to me as platinum and went through authentication process, but I do not see markings. Beautiful vintage piece.