Botswana's state-owned Okavango Diamond Company on Wednesday unveiled the biggest blue diamond ever discovered in the southern African country.
At 20.46 carats, the gem is one of the rarest stones in the world, and 'sits in the very top bracket of all-time historical blue diamond finds', the company said in a statement.
The oval-shaped gem has been named 'The Okavango Blue' in honour of the Okavango Delta, the country's wildlife-rich world heritage site.
It was discovered as a 41.11-carat rough stone in the Orapa mine and is Type IIb - one of the rarest natural diamonds.
'It is incredibly unusual for a stone of this colour and nature to have come from Botswana - a once-in-lifetime find, which is about as rare as a star in the Milky Way,' said Okavango Diamond Company managing director Marcus ter Haar.
'It is little surprise blue diamonds are so sought after around the world as only a very small percentage of the world's diamonds are classified as fancy colour,' he added.
Blue diamonds comprise only about 0.02 percent of mined diamonds but include some of the world's most famous jewels, including the famous Hope Diamond that passed through the hands of monarchs, bankers, heiresses and thieves before landing for all to see at the Smithsonian National Museum of Natural History in Washington D.C.
The diamonds' bright blue colour is attributed to the mineral boron, which was present in the rocks of oceans when the diamond was formed some 1 to 3 billion years ago.
Botswana is one of the world's largest producers of diamonds, which are its main source of income and account for about 80 per cent of its exports.
According to ter Haar just a few such blue stones have come to market in the last decade.
The company says the diamond is expected to be sold near the end of the year and could rival the Hope Diamond, which is insured for $250 million.
Although the Hope Diamond is larger - at 45.52 carats - the Okavango Blue has the edge on clarity.
The Gemological Institute of America graded the Okavango Blue as 'Very, Very Slightly Included,' or VVS2.
This means imperfections are 'difficult for a skilled grader to see under 10× magnification'.
TWEET YOUR COMMENT