The engagement ring belonging to the Duchess of Cambridge, and Diana, Princess of Wales before her, is believed to include a sapphire mined in the Sri Lanka in the 1970s. (Associated Press photo)
The world's largest blue star sapphire, weighing 1404.49 carats and valued at an astonishing $100 million, has been found in a mine in Sri Lanka.
Lankan gemologists say the sapphire was found in the city of Ratnapura, in southern Sri Lanka, which is known as the 'City of Gems'.
It has now been valued at $100 million with estimates that it could even be sold at auction for $175 million.
The owner of the sapphire, who wants to remain anonymous, told the BBC : "The moment I saw it, I decided to buy."
"When the stone was brought to me I suspected that it might be the world's largest blue star sapphire. So I took a risk and bought it," the anonymous owner said.
The current record for a blue star sapphire is 1,395 carats, the report said.
Armil Samnoon, a gem expert in Sri Lanka, said it was the biggest blue star sapphire in the world.
The sapphire has been named the 'The Star of Adam' by its current owner, after a Muslim belief that Adam arrived in Sri Lanka after being sent away from the Garden of Eden. It is claimed he then lived on the slopes of a mountain now known as Adam's Peak.
Blue star sapphires are so named because of the distinctive mark found at their centre.
Sri Lanka's Gem and Jewellery Association said in 2011 that the engagement ring for Catherine Middleton, the Duchess of Cambridge, included a sapphire mined in the country in the 1970s.
It was previously owned by Diana, Princess of Wales.