101-ct Allnatt Yellow Diamond Could Fetch $7.2m

(IDEX Online) - The 101.29-carat Allnatt diamond, described as one of the world's most significant fancy vivid yellow stones, is to be auctioned at Sotheby's Geneva, with an estimate of $6.2m to $7.2m.

The Type 1a gem, from South Africa, was named after the British racehorse owner and art collector Major Alfred Ernest Allnatt, who bought in in the 1950s. He had it mounted in a brooch by Cartier.

The Allnatt forms the heart of a flowerhead composed of openwork, brilliant-cut diamond-set petals enhanced with baguette diamonds.

It was last offered at auction in Geneva in May 1996 - as the 'Property of a Lady' - and sold for just over $3m. At the time it weighed 102.07 carats and was graded fancy intense yellow by the GIA.

It was subsequently repolished to its current 101.29 carats, which bought the color up to fancy vivid yellow.

The Allnatt diamond leads the Magnificent Jewels and Noble Jewels sale on May 14.  

Pic courtesy Sotheby's