One of the world's largest yellow diamonds will go under the hammer in Geneva next month, with the Sotheby's auction house hoping to rake in up to USD 25 million for the gem. The Graff Vivid Yellow, the colour of a daffodil and weighing 100.09 carats, figures among a wide range of pieces for sale at Sotheby's spring Magnificent Jewels and Nobel Jewels auction in the Swiss city on May 13. Read more