Exceptional gemstones, led by a 93.94-carat Paraiba tourmaline, will headline Sotheby’s Magnificent Jewels and Noble Jewels auction scheduled for November 8 in Geneva.

The Blue Lagoon – the largest Paraiba tourmaline of such quality to be offered at auction – is set in a bespoke diamond-studded necklace by renowned jeweller Adler. It has a pre-sale estimate of CHF1.36 million to CHF2.27 million (around US$1.5 million to US$2.5 million).

The gem’s impressive size and weight of 93.94 carats, combined with an attractive blue colour and excellent purity, make it extraordinary. “The few inclusion features found by microscopic examination and the analysed properties are consistent with those found in copper-bearing tourmalines from the Alto Ligonha district in Northern Mozambique,” Sotheby’s quoted gem lab SSEF as saying in its report. 

Other highlights of the sale include a 19.03-carat Kashmir sapphire ring valued at CHF910,000 to CHF1.36 million (about US$1 million to US$1.05 million) and a 103.62-carat fancy intense yellow diamond ring, called The Love Stone, estimated to fetch CHF1.82 million to CHF3.63 million (approximately US$2 million to US4 million).

Important signed jewellery from Cartier, Van Cleef & Arpels, Boucheron and Bulgari will also be presented at the sale.