It has been passed down for 800 years, from Chinese emperors to Marco Polo. The name of its current owner is a secret. But Thursday, hundreds of people will get the chance to buy the world's largest natural pearl on the market.
The "Arco Valley Pearl" 3.1 inches in length will be up for bidding at Abu Dhabi's Emirates Palace and on the Internet, where it is estimated to fetch up to $8 million.
The 575-carat pearl from 12th century Mongolia once belonged to Chinese emperors, Persian kings, the grandson of Genghis Khan and Marco Polo.
The value of the saltwater pearl is based on its size, color, weight, exclusivity, history and records of what people have been prepared to pay for similar precious items.
"It's 800 years old and it still takes your breath away," said Khaled al-Sayegh, 35, a jeweler from Abu Dhabi and chairman of the organizing committee for Thursday's event.
Arco Valley is only the biggest pearl up for sale in the world.
The 9.45-inch Pearl of Allah is the world's largest. It was found by a diver off the Philippine island of Palawan in 1934 and is stored in a museum in that country.
The Arco Valley pearl, named after a previous owner from Austria's Arco Valley family dynasty, is white with a touch of blue, mixed with pink and cream colors on its sides. It has been drilled three times: to fit among the jewels of an unknown woman's tiara, to go with a ceremonial mandarin suit and to fit a crown or turban decorated with precious stones belonging to a Persian king.
It has since been restored to its original shape.
Court documents prove the pearl was owned by Kublai Khan, the 13th century emperor of China and grandson of Genghis Khan. Experts believe Kublai Khan gave the pearl to Marco Polo as a gift.
Al-Sayegh said he and his partner brought the Arco Valley pearl to Abu Dhabi less than two months ago. He said the pearl was privately owned but did not disclose the owner's name.
At least 400 people from the Emirates, Gulf countries, China, India, Britain, the U.S. and Tahiti are expected to attend the auction.