Art Deco diamond, sapphire and ruby platinum three stone ring

Art Deco diamond, sapphire and ruby platinum three stone ring. Centred with a round Old European cut diamond in a rubover setting, flanked to one side with a trapezoid step cut sapphire in a rubover setting and flanked to the other side with a trapezoid step cut ruby in a rubover setting, to a geometric three stone design with flush settings, angular finish and linear shoulders which taper to a solid shank.