&#x27;The Cartier Pur Absolu Necklace&#x27; with a 30.21ct pear-shaped brilliant-cut diamond, which can also be set on a ring, and featuring a pearl, kite-shaped diamonds, pear-shaped diamonds, and brilliant-cut diamonds, set in platinum - for just two days, the Le Diamant exhibition opened its doors to a select few by appointment in London, Nov. 25, 2015