Botswana has announced the discovery of a large blue diamond weighing more than 20 carats.
State diamond company Okavango said Wednesday April 17th that it was the largest blue diamond ever discovered in Botswana.
It is "in the very top bracket of all-time historical blue diamond finds,” the company's statement said.
The company says the diamonds are expected to be sold near the end of the year.
Managing Director Marcus ter Haar said few of these blue stones have entered the market in the last decade.
The bright blue is due to the mineral boron, which was present in the ocean rocks when diamonds formed about one to three billion years ago.
Botswana is one of the largest diamond-producing countries, accounting for about 80% of its exports.