A SAPPHIRE AND DIAMOND RING, BY OSCAR HEYMAN BROTHERS   Set with a rectangular-cut sapphire weighing 13.30 carats, within a baguette-cut diamond frame, to the trapezoid and rectangular-cut diamond shoulders, mounted in platinum  With jeweller's mark for Oscar Heyman & Brothers. Art Deco or Art Deco style. Art Deco, Bracelets, Bijoux, Diamond Ring, Sapphire Diamond Ring, Diamond Jewelry, Solitaire Ring, Gold Diamond, Art Deco Jewelry