An 8ft (2.5m) sculpture of a diamond by US artist Jeff Koons is expected to raise around $12m (£6m) when it is sold at auction in November.
Blue Diamond is one of a series of five
Part of the artist's famed Celebration series, the blue "diamond" is in fact made of polished steel and chromium.
It will be auctioned at a Christie's sale of post-war and contemporary art in New York on 13 November.
An Andy Warhol portrait of Elizabeth Taylor is expected to fetch $25m (£12m) at the same auction.
Liz (Colored Liz) is one of the artist's iconic celebrity portraits from the mid-1960s.
It depicts the Hollywood star with exaggerated, blood-red lips and bright turquoise eye shadow - a reaction to rumours that the actress was severely ill and near death.
Earlier this year, Warhol's Green Car Crash (Green Burning Car I) set a new auction record for the artist when it sold for $71.7m (£35.6m).
If Blue Diamond reaches its estimate, it will represent a doubling of the previous record price paid at auction for Koons' work.
Koons took the pose from a publicity photograph
His most expensive piece to date is a sculpture of Michael Jackson and his pet monkey Bubbles, which fetched $5.6m (£2.8m) in 2001.
Created in 1988 from porcelain, it shows the superstar reclining with his arm around the monkey.
The controversial artist based his Celebration series, which he began in 1994, on a calendar of special events including holidays, birthdays, Valentine's Day and Easter.
Koons says the diamond represents an egg, which is being fertilised by the four gold-coloured prongs that hold it in place.
There are four other versions of the diamond. The red, pink and green sculptures are in private hands, while a yellow version is currently in production.