The world's second largest diamond has been discovered in Botswana. Canadian mining company Lucara Diamond used an advanced X-ray scanner to find a 2,492-carat diamond from the Karowe Diamond Mine. That's 17.58 ounces (498.4 g).
The largest gem-quality rough diamond ever found was the famous Cullinan Diamond, mined at the Premier Mine at Cullinan in the Transvaal Colony of South Africa in 1905. It weighed a record 3,106 carats (21.9 oz, 621 g). When cut, it yielded 105 stones, including the Great Star of Africa and others that became part of the British Crown Jewels.
Now in second place is a name from Botswana, but this time it is becoming a major player in the jewelry market.
The as yet unnamed gem was discovered using a technique called Mega Diamond Recovery (MDR) X-ray Transmission (XRT). Simply put, this consists of a conveyor belt where kimberlite ore from a diamond mine is spread evenly. This passes over an X-ray beam with a sensor on it.
Lucara Diamonds
A computer processes the data collected from the scan and creates a series of images that identify individual stones by shape and density. If the density is close to that of a diamond, an air jet blows the candidate into a collection box as the gem falls from the end of the arch.
The company says MDR XRT is particularly good at separating large, gem-quality diamonds and has found some unusual stones, including the 1,758-carat Sewelô diamond and the 1,109-carat Lesedi La Rona.
Lucara
To give some perspective, the largest synthetic diamond is the Celebration of India, which weighs in at a meager 75.33 carats. While synthetic diamonds have become easier to produce in recent years, they don't provide much competition for truly top-tier flawless diamonds.
This is partly due to technical difficulty and partly to the way the diamond market works. They maintain their value through scarcity, which is tightly controlled by the international diamond cartel, which combats smuggling and blood diamonds. Like diamond miners, synthetic diamond producers have a vested interest in not disrupting the market, so they tend to focus their efforts lower down the food chain with cheaper gems and industrial stones.
“We are delighted to have recovered this extraordinary 2,492-carat diamond,” said William Lamb, Lucara President and CEO. “This find not only showcases the extraordinary potential of our Karowe Mine, but also supports our strategic investment in state-of-the-art XRT technology. The ability to recover such a large, high-quality stone intact demonstrates the effectiveness of our diamond recovery approach and our commitment to maximizing value for our shareholders and stakeholders.”
Source: Lucara Diamond