A 9,000-year-old limestone mask, the oldest art object ever offered at Christie's, could sell for up to $600,000 (€477,402) when it goes under the hammer in June.
The rare Neolithic limestone mask, which evokes a human skull, is one of the earliest sculptural types to survive from antiquity, according to Christie's.
"Only very few of these masks are known," said Molly Morse Limmer, head of Christie's Antiquities department in New York. "All were found in the Judean desert, all were carved of limestone, and all represent the human skull."
The Judean desert's extreme dry conditions helped preserve the mask. Its function is a mystery but Ms Limmer said its origins dated to a time when complex societies were first evolving.
"No doubt they represent one of the earliest human attempts to connect with the spiritual world," she said. "Given the skeletal representation, it would be logical that they relate to death rituals or ancestor worship."
Small holes drilled along the perimeter suggest that hair might have been added, or they might have been used to secure the mask on the face of a dead person, or to a wall, pillar or statue, according to Christie's.
The 22.9cm mask, which is being sold by a New York collector, will be part of Christie's antiquities sale in New York on 8 June, when about 260 lots are expected to fetch about $8 million (€6.36m).
Antiquities have achieved some astounding prices in recent years. A Roman Imperial marble bust sold for $23.8m (€18.9m) in late 2010, nearly 10 times its pre-sale estimate, while a limestone lioness figure circa 3,000 BC fetched more than $57m (€45.3m) in 2007.
The art market itself has been on a roll, with records set this month for post-war art as well as the most expensive work ever sold at auction.
Other highlights of the sale include a Greek bronze mirror circa 300 to 350 B.C. which is estimated to sell for $600,000 to $900,000, (€477,402-€716,104).
Two Roman works of art each expected to sell for as much as $500,000 (€397 835). A marble torso of Venus dates to the 1st to 2nd century AD, while a marble head of Apollo is from the 2nd century AD.
