According to data published this week by the Kimberley Process (KP) Certification Scheme, Russia produced more volumes of carats than any other country in the world last year at 35 million carats worth $2.87 billion, but Botswana narrowly maintained its top producer by value rank due to the superior quality of gems it produced.

Botswana's diamond production fell to 20.5 million carats, worth $2.98 billion last year, from 22.9 million carats in 2011.

This closed down the gap on the value of diamonds produced by the two countries to as little as $110 million in 2012 from $1.23 billion in 2011. The softening of prices also contributed to Botswana's slide last year as the average price per carat of diamonds produced locally fell significantly to $144 from $170 in 2011 while prices of Russian produce increased to $82.3 per carat from $76 per carat in the previous year. "Botswana ranked as the top producer by value in 2012 despite registering a significant decline during the year. Botswana production by value fell 24 percent to $2.98 billion, while by volume its production dropped 10 percent to 20.5 million carats.

"In contrast, Russia maintained steady production to retain its position as the top producer by volume and closed the gap toward becoming the number one producer by value. The country's production by value rose 7 percent to $2.87 billion while by volume it fell 0.6 percent to 34.927 million carats," said the KP. Botswana production slowed as the country's flagship mine, Jwaneng was affected by a slope failure while Debswana, on the other hand, has been deliberately slowing production since the economic recession of 2008 to match market demand and maintain pressure on prices.

Botswana has traditionally held the top diamond producer by value perch, despite losing it to Russia temporarily in 2009, as Debswana drastically cut down production by close to 50 percent in the year. Debswana, which is jointly owned by De Beers and the Botswana government, reached peak production in 2006 at 34 million carats followed by 33 million carats in 2007 and 32 million carats in 2008 before cutting output rapidly to 17.7 million carats in 2009 due to the global economic downturn.

In 2012, the average price per carat of diamond produced locally also fell significantly to $144 from $170 in 2011 while prices of Russian produce increased to $82.3 per carat from $76 per carat in the previous year

Lesotho maintained its spot as the producer of the most expensive diamonds valued at $629.43 per carat. Globally, diamond production by value fell 10 percent to $12.64 billion in 2012 as rough prices slumped during the year, according to the data. By volume, global production rose 10 percent to 127.962 million carats. The average price achieved from the production fell 14 percent to $98.81 per carat.

Canada ranked third with production of 10.450 million carats valued at $2 billion as the average price of its goods fell 19 percent to $192.07 per carat. Angola came in fourth after mining 8.330 million carats valued at $1.11 billion, followed by South Africa with 7.077 million carats valued at $1.03 billion.

Other top diamond producers by volume included the Democratic Republic of the Congo (DRC) with 21.524 million carats valued at $183.1 million, Zimbabwe with 12.06 million carats valued at $644 million and Australia with 9.180 million carats valued at $269.4 million.