The world's largest uncut diamond sold for $ 53 million.

British jeweler Gaff said Tuesday it has purchased the world's largest uncut diamond -- roughly the size of a tennis ball -- for $53 million (44.5 million euros).

Canadian miner Lucara Diamond sold to Graft the 1,109-carat gem, the Lesedi La Rona, which was found in Botswana's Karowe mine in late 2015.

The Lesedi La Rona, the world's largest rough diamond, is 1,109 carats and was found in Botswana's Karowe mine in late 2015.

We are thrilled and honored to become the new custodians of this incredible diamond," said company chairman, Laurence Graft, in a statement.

"The stone will tell us its story, it will dictate how it wants to be cut, and we will take the utmost care to respect its exceptional properties."

Lucara confirmed the hefty price tag in a statement issued in Vancouver.

"The discovery of the Lesedi La Rona was a company defining event for Lucara," said William Lamb, president and chief executive of Lucara.

"It solidified the amazing potential and rareness of the diamonds recovered at the Karowe mine."

The rough diamond had previously failed to meet its reserve price of more than $70 million at a Southey's auction in 2016.

Graff is already the owner of a 373-carat diamond, which was bought earlier this year and formed part of the original stone.

Lesedi La Rona means "our light" in Botswana's Tswana language. It could be cut into smaller gems for jewelry or left whole in a private collection.

Diamond Quality Factors

One of the first things most people learn about diamonds is that not all diamonds are created equal. In fact, every diamond is unique. Diamonds come in many sizes, shapes, colors, and with various internal characteristics.

All polished diamonds are valuable. That value is based on a combination of factors. Rarity is one of those factors. Diamonds with certain qualities are more rare—and more valuable—than diamonds that lack them. 

         Jewelry professionals use a systematic way to evaluate and discuss these factors. Otherwise, there would be no way to compare one diamond to another. And there would be no way to evaluate and discuss the qualities of an individual diamond. Diamond professionals use the grading system developed by GIA in the 1950 s, which established the use of four important factors to describe and classify diamonds: Clarity, Color, Cut, and Carat Weight.

Lucara Diamonds’ open pit mine where Lesedi La Rona was found

So how do diamond sales benefit Botswana?

In many parts of Africa, diamonds haven’t been a blessing. They’ve been associated with exploitation, environmental destruction, corruption and “blood diamonds,” used to pay for civil wars in countries from Sierra Leone to the Democratic Republic of Congo,NPR  reported.

Botswana’s diamond story is different, said economist Keith Jefferis, former deputy governor of Botswana’s Central Bank.

Botswana shares joint-ownership of of its biggest mines with De Beers in an arrangement that guarantees it most of the profits. Botswana has also set up a progressive taxation system so other mining companies are taxed at higher rates when they get windfalls.

Founded in South Africa and now based in the U.K., De Beers sells approximately 35 percent of the world’s rough diamond production.

Historically there has been strong political consensus in Botswana that diamond revenue should only be used for spending on schools, roads, and getting water into people’s homes and farms

Mirny Diamond Mine

The second largest man-made hole in the world (surpassed only by the Bingham copper mine in Utah) is a diamond mine located on the outskirts of Miry, a small town in eastern Siberia. Excavation on the pit began in 1955, and today it is 1,722 feet (525 meters) deep, and 3,900 feet (1.25 kilometers) across. Stalin ordered construction of the mine to satisfy the Soviet Union's need for industrial-grade diamonds following the war.

The harsh, frozen Siberian landscape made working on the mine a difficult proposition at best. Jet engines were turned on the unyielding permafrost in order to melt it; when that failed, explosives were used. During its peak years of operation, the Miry mine produced over 10 million carats of diamonds annually, a good percentage of which were gem-quality.

Although open pit mining has ceased here, mining work is continuing by underground methods. The massive 20-foot (6 meter) tall rock-hauling trucks that service the Miry mine travel along a road that spirals down from the lip of the hole to its basin.

Though it has been said that the airspace above the mine is off-limits to helicopters, after "a few accidents when they were 'sucked in' by downward air flow," there is no evidence to substantiate the claim.