The world's second-largest gem quality diamond has been discovered in Botswana, Canadian mining company Lucara Diamond said. "Sergio", a black carbonado diamond found in Brazil in 1893 still remains the largest by weight.
The 1,111-carat stone was recovered from its Karowe mine, about 500km (300 miles) north of the capital, Gaborone. It's described as "gem" quality and is almost as big as a tennis ball. One carat is equal to a fifth of a gram, so Lucara's 1,111-carat diamond weighs 222 grams. It is the biggest diamond to be discovered in Botswana and the largest find in more than a century.
That's the biggest gem-quality diamond discovered since the famed Cullinan measuring more than 3,000 carats was found in South Africa in 1905. The Cullinan was subsequently cut into smaller pieces, with the two largest portions incorporated into Britain's Crown Jewels.
Botswana is the world's largest producer of diamonds and the trade has transformed it into a middle-income nation.
Helgi Library 
