A pearl necklace realised $5m in Christie's Magnificent Jewels auction in New York on April 14 - a world record for a natural coloured example.
The four-strand lot exceeded an estimate of $4.5m by 11.1%.
Rahul Kadakia, Christie's international head of jewellery, commented: "Natural pearls achieved very strong prices and a world-record US$5 million was realised for a four-strand natural coloured pearl necklace.
"There was spirited bidding for coloured pink and blue diamonds along with all of the JAR creations offered in the auction."
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