Showing posts with label Diamonds. Show all posts
Showing posts with label Diamonds. Show all posts

Sunday, 1 March 2026

South African diamond mining company files for bankruptcy after five miners killed in flood.

South African mining company Ekapa Minerals has filed for liquidation following the death of five miners at its Ekapa Joint Shaft Mine at Kimberly in Northern Cape Province, South Africa, on 17 February 2026. The miners have been missing presumed dead since a slurry of water and mud rapidly filled the section of the mine where they were working. The area where the incident occurred was located 890 m below ground, and had only recently been opened up, and life support systems had been installed, but the sudden nature of the flood has led the mine operators to conclude that the incident was not survivable, and, following several days of attempts to reach and clear the site, that there is little hope of recovering the bodies of the lost miners.

A mine rescue team entering the Ekapa Joint Shaft Mine site this week. SABC News.

Floods and inrushes typically occur when miners accidentally break through into pockets of water and gas trapped within rocks. Since such buried waters are often under high pressure due to the weight of rocks above them, they tend to escape into the mine rapidly, and on occasion explosively, leading to a highly dangerous situation in which miners are often rapidly overwhelmed. Such inrushes can also occur when miners encounter flooded disused mineworkings, a danger in areas where mining has occurred for a long time but good records have not been kept. The Ekapa mine had a history of flood inrush events, and the company had been warned by a parliamentary committee in 2025 that steps needed to be taken to avoid future events of this kind.

The Ekapa Joint Shaft Mine site. SABC News.

The closure of the mine is predicted to result in the loss of about 1200 jobs, a crisis for the city of Kimberly, which has a population of just under 97 000 people, and is already suffering from high unemployment rates due to the decline of the diamond industry. Furthermore, workers from the site report that they have not received their salaries for the month of February 2026, placing many of the in a very difficult situation financially. 

Ekapa Minerals purchased the Joint Shaft Mine from mining giant De Beers in 2016, and at the time of closure it was the last surviving diamond mine in Kimberly. In theory, the site could be sold on to another mining company following the liquidation process, but it is unclear if a buyer will be found given the mine's problems and a fluctuating diamond market.

The location of Kimberley in Northern Cape Province, South Africa. Google Maps.

Kimberly was founded in the 1870s following the discovery of diamonds in the area, and rapidly became a centre of wealth in the Cape Colony, opening South Africa's first stock exchange in 1881, and becoming the second city in the world to install electric street lighting the following year. However, in recent years the city's mines have closed one-by-one as the industry has become less viable. The long history of mining in the area means that there are no diamonds left close to the surface, and while they can still be found at greater depths, these are generally fairly small, making it hard for these mines to compete with either shallow, open pit mines elsewhere, or artificial lab-grown diamonds.

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Saturday, 24 August 2024

Newly discovered diamond from Botswana is thought to be the third largest ever found.

The Lucara Diamond Company has announced discovering what is believed to be the third largest diamond ever found at its Karowe Mine in eastern Botswana, in a press release issued on 21 August 2024. The diamond weights 2492 carats (498.4 grams), making it larger than the previous third largest diamond ever discovered, the 1758 carat Sewelô Diamond, which was discovered at the Karowe Mine in 2019.

The new, and as yet unnamed, diamond revealed by Lucara Mining thing month. Lucata Mining.

The largest diamond ever found is the Sergio Diamond, found at Lençóis in Bahia State Brazil, in 1895, by Sérgio Borges de Carvalho, after whom it is named, which weighed 3167 carat (633.4 g). Surprisingly, the Sergio Diamond was not found within a diamond mine, but on the surface. The Sergio Diamond was a carbonado, a type of diamond with a black colour, a micro-porous structure, and a high graphite and amorphous carbon content, as well as frequently containing inclusions of other minerals or metals. Notably, some of the inclusions found in carbonado diamonds are extremely rare on Earth, and they have very low proportions of the isotope carbon¹³ compared to other diamonds, as well as radioactive inclusions, again not found in other diamonds. All caronado diamonds subjected to uranium-lead isotope dating have been found to be about 3 billion years old, and almost all carbonado diamonds come from two locations, Brazil and the Central African Republic. This has led to speculation that these diamonds are derived from an extra-terrestrial body which impacted the Earth in the distant past, although no hypothesis as to how such a body could have formed has ever gained widespread acceptance. Because of their hardness, carbonado diamonds were widely sought for use in drill bits in the nineteenth century, although they have been replaced by more modern materials today. Despite its exceptional size (most carbonado diamonds are smaller than a pea), the Sergio Diamond was sold for £6400 in London in September 1895, then broken up to make diamond drill bits.

An engraving of the Sergio Diamond published in Popular Science Monthly in 1906. Wikimedia Commons.

The second largest diamond ever discovered, and the largest gemstone-quality diamond, was rhe Cullinan Diamond found at Cullinan in what is now Gauteng Province, South Africa, in April 1905, which weighed 3106 carat (621.2 g) when it was found. The Cullinan Diamond was purchased by Louis Botha, the Prime Minister of the Transvaal Colony, and given to the British King Edward VII, who had it cut into nine large gemstones and a number of smaller fragments known as 'The Brilliants'. The largest of these cut stones, known as Cullinan I or the Star of Africa, has a mass of 530.4 carat, and is mounted on the Sceptre with Cross, part of the British Crown Jewels, which is carried by the monarch at their coronation.

(Left) The uncut Cullinan Diamond in 1908. (Right) The Star of Africa Diamond in the Sceptre with Cross in 1919. Wikimedia Commons.

Six of the eight largest diamonds ever dug up have been discovered at the Karowe Mine since 2015; this is not a coincidence. but marks the introduction of new technology pioneered at the Karowe Mine. Modern mines typically use crushing machinery to extract diamonds from their parent rock, but this is generally thought to break up a significant proportion of larger diamonds. The Karowe Mine uses X-ray fluorescence technology to scan ore before it passes into the crushing equipment, thus allowing for the machinery to be stopped and particularly large diamonds to be recovered. 

Flow chart showing the processing and sorting of diamonds at the Karowe Mine. Lucara Diamonds.

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Sunday, 13 August 2023

Seventh largest diamond ever found discovered in Botswana.

The Lucara Diamond Company has announced discovering what is believed to be the seventh largest diamond ever found at its Karowe Mine in eastern Botswana, in a press release issued on 8 August 2023. The diamond is described as weighing 1080.1 carats (216.02 g), and to measure 82.2 x 42.8 x 34.2 mm. Importantly, the gemstone is reported to be a Type IIa top white diamond, which is to say a diamond with almost no impurities, a type of diamond which make up only about 1-2% of all diamonds discovered, and which are correspondingly more valuable than other diamonds of similar size. 

The new Lucara diamond. Lucara Diamonds.

The largest diamond ever found is the Sergio Diamond, found at Lençóis in Bahia State Brazil, in 1895, by Sérgio Borges de Carvalho, after whom it is named, which weighed 3167 carat (633.4 g). Surprisingly, the Sergio Diamond was not found within a diamond mine, but on the surface. The Sergio Diamond was a carbonado, a type of diamond with a black colour, a micro-porous structure, and a high graphite and amorphous carbon content, as well as frequently containing inclusions of other minerals or metals. Notably, some of the inclusions found in carbonado diamonds are extremely rare on Earth, and they have very low proportions of the isotope carbon¹³ compared to other diamonds, as well as radioactive inclusions, again not found in other diamonds. All caronado diamonds subjected to uranium-lead isotope dating have been found to be about 3 billion years old, and almost all carbonado diamonds come from two locations, Brazil and the Central African Republic. This has led to speculation that these diamonds are derived from an extra-terrestrial body which impacted the Earth in the distant past, although no hypothesis as to how such a body could have formed has ever gained widespread acceptance. Because of their hardness, carbonado diamonds were widely sought for use in drill bits in the nineteenth century, although they have been replaced by more modern materials today. Despite its exceptional size (most carbonado diamonds are smaller than a pea), the Sergio Diamond was sold for £6400 in London in September 1895, then broken up to make diamond drill bits.

An engraving of the Sergio Diamond published in Popular Science Monthly in 1906. Wikimedia Commons.

The second largest diamond ever discovered, and the largest gemstone-quality diamond, was rhe Cullinan Diamond found at Cullinan in what is now Gauteng Province, South Africa, in April 1905, which weighed 3106 carat (621.2 g) when it was found. The Cullinan Diamond was purchased by Louis Botha, the Prime Minister of the Transvaal Colony, and given to the British King Edward VII, who had it cut into nine large gemstones and a number of smaller fragments known as 'The Brilliants'. The largest of these cut stones, known as Cullinan I or the Star of Africa, has a mass of 530.4 carat, and is mounted on the Sceptre with Cross, part of the British Crown Jewels, which is carried by the monarch at their coronation.

(Left) The uncut Cullinan Diamond in 1908. (Right) The Star of Africa Diamond in the Sceptre wirh Cross in 1919. Wikimedia Commons.

The third largest diamond ever found is the Sewelô Diamond, recovered at Lucara's Karowe Diamond Mine in Botswana in April 2019, which weighs 1758 carats (352 g). This was the largest diamond ever found in Botswana, and its name was chosen by a competition organised by Lucara, meaning 'rare find' in Setswana. The Sewelô Diamond was purchased by the French fashion house Louis Vuitton, with the intention of having it cut into smaller gems.

The Sewelô Diamond. The diamond has a black crust formed of pitted carbon, but is gemstone quality beneath. Lucara Diamonds.

The fourth largest diamond ever discovered is an unnamed diamond found at Lucara's Karowe Mine in June 2021. This diamond had a mass of 1174.76 carats, and measuring 77 x 55 x 33 mm. This gem is considered to be of variable quality, although with a significant proportion of high quality diamond.

An unnamed diamond found at Karowe Mine in June 2021. Lucara Diamonds.

The fifth largest diamond ever discovered was the Lesedi De Rona Diamond, found at the Karowe Mine in November 2015. Like the new diamond, this was a Type IIa top white diamond, and has a mass of 1111 carat (222.2 g) when it was found. At that time, it was the largest diamond ever found in Botswana, and the third largest diamond ever found, prompting Lucara Mining to organise a national competition in Botswana to chose a name. The winning name, Lesedi De Rona, translates as 'Our Light' in Setswana, and was chosen by Thembani Moitlhobogi of Mmadikola. The diamond was purchased by the London-based jeweller Graff, and cut to form one large diamond, the 302.37 carat Graff Lesedi De Rona Diamond, and 66 smaller gemstones.

The uncut Lesedi De Rona Diamond in 2015. Lucara Diamonds.

The sixth largest diamond ever discovered was found at the Debswana-owned Jwaneng Mine in southern Botswana in June 2021, and had a mass of 1098 carat (219.6 g), measuring 73 x 52 x 27 mm. 

The unnamed diamond found at Debswana's Jwaneng Mine in southern Botswana in June 2021. Reuters.

Thus, the new diamond is the seventh largest diamond ever discovered, the sixth largest gemstone quality diamond ever discovered, the sixth largest diamond ever found in Africa, the fifth largest diamond ever found in Botswana, the fourth largest diamond extracted from the Karowe Mine, and one of only seven diamonds ever found with a mass of greater than 1000 carat. 

That five of these seven diamonds have been found in Botswana, and four of them from a single mine, since 2015 is not a coincidence. but marks the introduction of new technology pioneered at the Karowe Mine. Modern mines typically use crushing machinery to extract diamonds from their parent rock, but this is generally thought to break up a significant proportion of larger diamonds. The Karowe Mine uses X-ray fluorescence technology to scan ore before it passes into the crushing equipment, thus allowing for the machinery to be stopped and particularly large diamonds to be recovered. 

Flow chart showing the processing and sorting of diamonds at the Karowe Mine. Lucara Diamonds.

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