This is a stunning very scarse Yomut necklace, almost identical to the one in the Metropolitan Museum in New York https://www.metmuseum.org/art/collection/search/141594 Its 19th/early 20th century from the Yomut tribe of Turkmenistan and Uzbekistan. This jewellery was created to make a sumptuous show for the women of the great fearless warriors and horsemen of these regions.  Made of silver with firegilded and gold stamped applied decorations with mostly red glass stones.  (red is often asociated with purity of blood, fertility and health). Each of the side panels is 27cms , Total length with chain is 70cms/27inches. Height of pendant including dangles 13cms, width 11cms. Weight 246gms. The shape of the pendant is a double bird shape, a motif also used in Tekke necklaces- - a related tribe.
By the end of the 19th century these tribes were conquered by the Russians.