Vintage Sterling Silver Necklace

Very unique solid sterling silver necklace. It’s hard for me to tell the age on this one. The chain is indicative of art deco period, however the circle pieces have 925 Sterling stamped and typically 925 was not used till a later date. So I really can’t say for sure what country this piece was made or the year. It’s beautiful. The only part that is not sterling is the spring ring clasp. Almost every piece is marked 925 Sterling. It’s 15” in length, and weighs 24.5 grams. It has been tested and guaranteed sterling silver necklace. I did polish the back