An assortment of Schlumberger jewels up for auction at Bonhams New York in October. Photo courtesy Bonhams

A sapphire and diamond ring, Jean Schlumberger, Tiffany & Co. Photo courtesy Bonhams

centering an oval-cut sapphire, within a circular and marquise-cut floral cluster surround, enhanced with polished gold wire detail; signed Tiffany for Tiffany & Co., Schlumberger; sapphire weighing approximately: 12.70 carats; estimated total diamond weight: 2.60 carats; mounted in eighteen karat gold and platinum; size 6. Estimate: US$ 40,000 - 60,000 5€30,000 - 44,000) (£25,000 - 38,000)

Accompanied by AGL report #CS 56555, dated September 4, 2013, stating the sapphire is: Ceylon (Sri Lanka) origin, with no evidence of heat or clarity enhancement.

An eighteen karat gold, enamel and gem-set 'camel' brooch, Jean Schlumberger, Tiffany & Co.. 

the textured gold camel with a cultured pearl headdress, blue pailloné enamel hump and circular-cut diamond, oval-cut pink sapphire and polished gold ornaments; signed Tiffany for Tiffany & Co., Schlumberger; gross weight approximately: 55.8 grams; length: 2in. Estimate: US$ 8,000 - 12,000 (€5,900 - 8,900) (£5,000 - 7,500)

An assortment of Schlumberger jewels up for auction at Bonhams New York in October. Photo courtesy Bonhams