A Christie's employee displaying a fancy yellow cushion modified brilliant-cut diamond of 118.05 carats during a press preview on Thursday, for an upcoming auction by Christie's in Geneva, Switzerland.

The diamond is expected to attract bids of between US$2.5 million (S$3.4 million) and US$3.5 million at the Magnificent Jewels auction in Geneva next Wednesday.

The diamond was mentioned in Ian Balfour's book Famous Diamonds, first published in 1987, in his "The World's Largest Cut Diamonds List".

Cushion modified brilliant-cut diamonds often have exceptional sparkle, reminiscent of the "sparkling water" or "crushed ice" appearance of a well-cut square diamond.

Fancy colour diamonds are extremely rare and tend to be found as small stones weighing less than a carat.

For every 10,000 colourless diamonds of gem quality, only one natural colour diamond will be found.

In terms of coloured diamonds, however, yellow diamonds are the most commonly found, with gem experts estimating that yellow diamonds make up 60 per cent of all of the coloured diamonds in the world.

Since it is common compared with its other colour diamond counterparts, a yellow diamond will garner a lower price for buyers, making it perfect for a bride looking for a coloured diamond that does not break the bank.