Entourage ring in white gold, platinum, sapphires and diamonds

Rosette ring in 18 carat white gold and platinum, decorated in its center with an old-cut diamond, in a surround of rose-cut diamonds and navette sapphires (probably synthetic). French Art Deco work, Circa 1935. Condition: slight micro scratches on the platinum and gold parts, slight shock on the central diamond, see photos.