The Graff ruby realised $8.6m in a sale at Sotheby's Geneva on November 12, an increase of 11.5% pa on the $3.6m it sold for in 2006.

The Graff ruby made $8.6m at Sotheby's Geneva

Described as "pigeon blood red", the stone is named for its previous owner - jewellery magnate Laurence Graff.

Christie's also held a major jewellery sale on November 12, with the Blue Belle of Asia setting a $17.2m record for a sapphire.

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