Ancient necklace early ‘900 ‘Concertino’ in Gold 9 kt and Enamels

Necklace formerly called ‘Concertino’ Mid’800 era in 9 kt gold. It has a large central pendant in perforated foil decorated with an enamelled R in shades of blue and light blue, a letter that recurs in many jewels of the time. Very rare and unobtainable popular jewel in excellent condition
Necklace length: about 64 cm
Central dimensions: about 7.8 x 5 cm
Weight: 20.60 gr