A British jeweller today unveiled the largest emerald-cut diamond in the world, worth tens of millions of pounds.
The stunning 302.37 carat diamond, named the Graff Lesedi La Rona, is the highest clarity stone ever graded by the Gemological Institute of America (GIA).
It was cut from an enormous rough diamond which jeweller Graff paid $53 million - the equivalent of £40 million - for 18 months ago.
The value of the newly-unveiled gemstone has not been revealed, but a 163.41 carat diamond sold for nearly £26 million two years ago.
The value of the latest stone - the principal diamond from the 1,109 carat Lesedi La Rona rough diamond - will be "considerably more", experts believe.
Price glitch sees actual helicopter on sale for just £550 - that's 99.9% off
Laurence Graff said: “My love affair with diamonds is life-long and crafting the Graff Lesedi La Rona has been an honour.
"This diamond, our diamond, is beyond words.”
The precious stone was discovered at the Lucara Karowe mine in Botswana, becoming the largest gem quality rough diamond found in more than a century.
Mr Graff said: “There is a huge amount of good fortune involved in unearthing a rough diamond of this extraordinary beauty and importance.
"Year after year can go by… month after month can pass… with nothing… then you get lucky."
It was named Lesedi La Rona - which means “Our Light” in Tswana, the official language of Botswana.
Debenhams gift cards, refunds and online orders - your rights as chain collapses
The size of the diamond prove a challenge for gemmologists, the company said, with no room for error.
Each cut was made with precise lasers, and hundreds of hours were spent producing the stunning product.
A further 66 "satellite" diamonds were cut from the massive stone.
Mr Graff said: ”Cutting a diamond of this size is an art form, the ultimate art of sculpture.
“It is the riskiest form of art because you can never add and you can never cover up a mistake, you can only take away. You have to be careful and you have to be perfect.”
