Around 1920/30. Platinum. In the center one light, milky opal of oval shape with colourplax in red, blue and green (approx. 26 x 17 mm), framed by 2 diam. in old cut and 76 diam. in 8/8 cut in total approx. over 2 ct. H-I.vs-P. Needle and mounting reverse and safety chain added. 51 x 30 mm, weight approx. 14 g.