Jean Schlumberger for Tiffany & Co. Ruby and diamond 'Sixteen Stone' ring, designed as a continuous line of eight pairs of circular-cut rubies and brilliant-cut diamonds between X-shaped wire motifs, the diamonds together weighing approximately 0.64 carats, mounted in platinum and 18ct gold, size K, signed Schlumberger, Tiffany & Co. Other Notes: a Schlumberger classic, this iconic design is strongly defined by a repeating X as an ideogram for harmony and balance.