Diamonds – Page 2

Alrosa’s $240m Plan to Dig Deeper at Udachny Mine

Alrosa is to invest RUB 20bn ($240m) digging deeper to extend the life of the vast underground Udachny mine, just outside the Arctic Circle, until at least 2055.

Mining will eventually take place more than 1km below the surface, extracting 4.1m tonnes of ore annually. The target horizon – the level where mining operations are planned – is 1.13 km below the surface ( at an absolute elevation of -780 m, when taking the surface elevation as a baseline).

Alrosa CEO Pavel Marinychev says annual profit from the planned expansion is estimated at almost RUB 6bn ($73m) a year.

Udachny opened as open-pit mine in 1967 and switched to underground operations in 2014, producing over 10 per cent of Alrosa’s total output. It was due to reach the end of its life in 2039.

Alrosa said the investment committee had approved the project. Udachny is one of the world’s largest kimberlite pipes. Trucks take over 30 minutes to reach the bottom, currently 680 metres below the surface.

“The implementation of the investment project will enable us to significantly extend the duration of mining at the deposit, which currently produces more than 10 per cent of Russian rough diamonds,” said Marinychev.

“From 2025 through 2055, 4.1 million tonnes of ore will be mined here annually and profit is estimated at almost 6 billion rubles per year.”

Source: IDEX

Botswana: Zero Sales in Emergency 1m-carat Tender

Okavango, Botswana’s state-owned diamond company, failed to sell a single stone in an unprecedented “emergency” tender of 1m carats last Thursday 25 September.

The auction was aimed at raising revenue for the government, which had been severely hit by the slump in demand for natural diamonds, but buyers weren’t prepared to pay the reserve prices.

Okavango Diamond Company (ODC) has canceled a number of tenders since November 2024 because of weak demand. It had planned to hold two further ad hoc tenders by the end of this year, but may now have to reconsider.

ODC usually holds about 10 scheduled online spot auctions annually for registered buyers. Last week’s ad hoc tender was a marked departure from the norm.

ODC spokesman Dennis Tlaang said ahead of the tender that it wouldn’t be selling at prices that would have “a negative impact on the market”.

The company now sells 30 per cent of the rough output from Debswana, the 50/50 joint venture between the Botswana government and De Beers.

Source: IDEX

Antwerp Negotiates Zero US Tariff for Polished Diamonds

The US has agreed to ditch its 15 per cent tariff on imports of diamonds polished in Antwerp and elsewhere in the EU.

They will be zero-rated, following intensive lobbying from the AWDC (Antwerp World Diamond Centre).

The exemption, made in a US executive order, means Antwerp’s 350 or so diamond polishers are now subject to zero tariffs on US imports, while the thousands of polishing units in India are currently subject to a 50 per cent tariff.

The 15 per cent tariff was introduced on 1 September as part of a global move announced by US President Donald Trump. The new diamond exemption is effective retroactively from that date.

AWDC described it as a “tremendous boost for the Antwerp diamond industry,” one which could pave the way for other diamond countries to negotiate lower tariffs with the US.

CEO Karen Rentmeesters (pictured) said: “The agreement is of vital importance and strengthens our competitiveness as both a trading and polishing hub. For goods of European origin – polished in Antwerp – which account for half of all polished diamond exports to the U.S., the 15 per cent tariff will no longer apply.

“By setting this precedent, we have opened the door for other diamond-producing and polishing countries to negotiate similar arrangements in the near future.”

Diamonds polished in an EU country are now included on the list of exemptions summarized in so-called ‘Annex II,’ which outlines products that can be exempted once a bilateral trade agreement with the U.S. is reached.

Source: IDEX

Diamonds as Time Capsules: Rare Inclusions Reveal Hidden Chemistry Deep Within Earth’s Mantle

Two extraordinary diamonds from South Africa have provided scientists with a rare glimpse into the hidden chemistry of Earth’s mantle—nearly 300 kilometres beneath the surface.

A research team from the Hebrew University of Jerusalem has identified the first direct evidence of nickel-iron metallic alloys and nickel-rich carbonates at these extreme depths. The discovery was made by examining tiny inclusions preserved inside diamonds from the Voorspoed mine in South Africa.

Diamonds as Nature’s Record Keepers

While diamonds are prized for their beauty, their true scientific value often lies in what they conceal. Inclusions—whether microscopic minerals or metallic alloys—serve as natural records of deep-Earth processes that would otherwise remain invisible.

“These diamonds act as tiny time capsules, preserving a rare chemical reaction that would otherwise disappear,” explained lead researcher Yaakov Weiss.

The inclusions confirm the diamonds’ origins in the deep upper mantle and shallow transition zone, at depths of 280–470 kilometres.

Unlocking Diamond Formation

The study revealed an unusual coexistence of nickel-iron alloy and nickel-rich carbonate within the same inclusions. Normally, these materials would react instantly and could not exist side by side. Their preservation points to a process known as a metasomatic redox-freezing reaction, in which oxidised, carbon-rich melts infiltrate metal-bearing mantle rock.

This finding strengthens the theory that diamonds can form from reactions between carbonates and reduced metals in the mantle—a mechanism first suggested by evidence at shallower depths.

It may also explain why some natural diamonds contain nickel atoms within their crystal structure, solving a mystery that has long puzzled geologists.

Insights into Volcanoes and Kimberlites

The implications extend beyond diamond formation. The reactions preserved within these inclusions suggest that the mantle becomes enriched with elements like carbon and potassium. This enrichment may be a critical step in generating kimberlite magmas—the volcanic eruptions that transport diamonds to the surface.

A Scientific Treasure

For the DCLA, this discovery highlights yet another dimension of diamond’s significance. Beyond their role as treasured gems, diamonds are windows into Earth’s inaccessible depths, preserving geological secrets for millions of years.

As Yaakov Weiss put it:
“Diamonds act as tiny time capsules, capturing a moment of mantle chemistry in action.”

$4m Estimate for Frisbee-Sized Gold and Diamond “Coin”

A huge, one-of-a-kind “coin” created to mark Queen Elizabeth II’s Platinum Jubilee is to be auctioned with a high estimate of $4m.

The Crown Coin, commemorating her 70 years on the throne in 2022, was struck from 3.61 kg of 24-carat gold and set with 6,426 GIA-certified diamonds weighing a total of 483.57 carats. At 235mm across it is almost the size of a standard frisbee.

At the center is a 1kg gold coin – legal tender with a face value of Â£10,000 – surrounded by 10 smaller coins bearing official portraits from Queen Elizabeth II’s reign.

The “coin” was created by The East India Company Bullion Ltd, which makes commemorative and collectible bullion coins, and takes its name from the long-dissolved East India Company, which played a major role in establishing British imperialism in India.

Stanley Gibbons Baldwin’s, the London-based auction house specializing in coins and stamps, will offer it for sale on 25 September, with an estimate of Â£2m to Â£3m (USD 2.7m to 4.0m).

Source: IDEX

Rio Tinto ends diamond era with historic final auction

Rio Tinto is auctioning its final collection of rare diamonds from its closed Argyle mine in Australia and the soon-to-shutter Diavik operation in Canada.

The tender, called Beyond Rare, includes 52 lots totalling 45.44 carats and marks the end of an era for two of the world’s most celebrated diamond mines.

The centrepieces are six diamond sets selected to represent the peak of production from the East Kimberley region of Western Australia and the Northwest Territories of Canada. The tender also features 39 individual stones and seven curated sets.

Rio Tinto Diamonds’ general manager of sales and marketing, Patrick Coppens, called the auction a historic moment. “It is hard to overstate the importance of this final collection,” he said in the statement. “No other mining company in the world has custody of such an exquisite range of diamond colours, shapes and sizes.”

Rio Tinto closed Argyle in 2020, ending production of the famed pink, red and violet stones that made the mine world-renowned. Although Argyle accounted for about 75% of Rio’s diamond output, the impact on the company’s earnings was minimal, with diamonds contributing only about 2% of revenue. Diavik, the miner’s last diamond asset, is scheduled to close in 2026.

The collection includes one GIA Fancy Red diamond, 12 Fancy Violet, and 76 Fancy Pink and Purple-Pink stones from Argyle’s legacy inventory. From Diavik, highlights include two flawless D-colour white diamonds, an emerald cut weighing 5.11 carats and a pear shape of 3.02 carats. Both of them were cut from the same rough stone.

Rio Tinto ends diamond era with historic final auction — Collection includes one GIA Fancy Red diamond, 12 Fancy Violet, and 76 Fancy Pink and Purple-Pink stones from Argyle’s legacy inventory.

The tender also features a Fancy Vivid Yellow diamond weighing 6.12 carats.

The diamonds will tour Hong Kong, Australia and Antwerp before bids close on October 20. Industry insiders expect strong competition from top jewellers, collectors and connoisseurs.

Source: Mining.com

Diamond selling processes are outdated and hurting producers, trader says

The sale of diamonds through tenders and auctions is opaque and inefficient and should be revamped for producers to earn more and to survive the current price slump, a leading gem trader said on Thursday.

Oded Mansori, co-founder and managing partner of Belgian gem trader HB Antwerp, said the impact on producers could be reduced by doing away with inefficiencies in the industry.

The diamond market is currently going through a prolonged downturn with demand hurt by global economic uncertainty and the rising popularity of lab-grown stones.

Producer countries such as Botswana have been hard hit by lower revenues, while miners such Burgundy and Lesotho’s biggest diamond mine Letseng have had to lay off workers.

“For years, miners relied on tenders and auctions, systems that look efficient on paper but in practice resemble a casino,” Mansori said in a statement, as the industry battles a crisis considered to be its deepest in history.

“Rough stones are pushed into opaque markets where value is anyone’s guess. When global demand softens, as it has in cycles over the last decade, producers are left exposed. Workers pay the price, while shareholders watch assets decline,” he added.

Rough diamonds are typically sold through a competitive bidding system where buyers place confidential bids on individual stones or parcels.

Mansori, whose company operates a profit-sharing model with miner Lucara Diamond Corp, says producers’ revenues should be tied to the eventual polished value of its stones “rather than gambling on rough sales in opaque auctions”.

Under its partnership with Lucara, HB Antwerp buys stones of 10.8 carat quality and above from the Toronto-listed company’s Karowe Mine in central Botswana at prices based on the estimated polished value of each diamond.

HB Antwerp accounted for 72% of Lucara’s $74-million diamond revenue in the six months to June 30, up from 65% the year before.

The trader says producers can earn up to 40% more revenue if they sell through this model.

Source: Miningweekly

After 15 Years, Disputed Diamonds Finally being Sold

Rough diamonds that were locked in a 15-year legal dispute in Zimbabwe are finally being sold.

The UK miner Vast Resources is offering parcels totaling 135,000 carats at a series of public and private tenders from now until the end of October.

Vast surrendered the gems in 2010 amid allegations it had exploited diamonds on mining claims previously owned by De Beers, which withdrew from Marange in 2006, saying it had failed to find viable reserves.

Vast Resources (then known as African Consolidated Resources) subsequently discovered massive alluvial diamond deposits there, which prompted the Zimbabwe government to revoke its mining licenses within months, and evict it.

The diamonds, held at Zimbabwe’s central bank since 2009, were finally handed back to Vast in April of this year.

They have undergone an extensive cleaning process in Dubai to remove multiple layers of metallic silicates and mineral coatings. As a result, around 6,000 carats initially classified only as industrial diamonds have been upgraded to gem quality.

In an update (on 15 September) Vast spoke of “a unique opportunity to most effectively realize value from the long-awaited parcels from the historic settlement and could open further opportunities for the company in the future”.

Source: IDEX

Lab Growns – without the High Pressure or Temperature

Researchers at the University of Tokyo say they’ve found a way to make tiny diamonds without the need for high temperature or high pressure conditions – unlike current lab grown technology.

They use electron beams to break and remake bonds in adamantane (C10H16), a carbon molecule in which atoms are arranged in a pattern very similar to the atomic structure of diamond.

The process takes tens of seconds under transmission electron microscopy conditions in a vacuum (low-pressure chamber)

A team led by Professor Eiichi Nakamura, of the Department of Chemistry, has published its findings in the journal Science, in an article entitled Rapid, low-temperature nanodiamond formation by electron-beam activation of adamantane C-H bonds.

It explains how the controlled electron irradiation of adamantane produces defect-free nanodiamonds.

The breakthrough process is aimed at creating tiny diamonds for high-tech industries, scientific research, and medical fields, rather than larger gem-quality stones.

It works through gradual assembly of diamond lattice from adamantane molecules under prolonged electron irradiation, which naturally limits the size to nanodiamonds currently.

Larger diamond growth would require controlling fusion of these nanocrystals and sustained lattice perfection over much longer times and at a larger scale.

Gem quality lab growns are created either using High Pressure High Temperature (HPHT) or Chemical Vapor Deposition (CVD), which uses high temperatures and low pressure.

Source: IDEX

CIBJO U-Turn: Don’t Say Lab Grown, Say Synthetic

The World Jewellery Confederation (CIBJO) is set to reverse a decision made in 2010 – and insist that non-natural diamonds are labelled as “synthetic”.

It says the terms “laboratory-grown” and “laboratory-created” should be removed from the Diamond Blue Book – the de facto standard for diamond terminology, grading and trade practices – and from all relevant ISO Standards.

In addition, the 4Cs grading system should be used only for natural diamonds (as the GIA is now doing).

Udi Sheintal (pictured), president of CIBJO’s Diamond Commission, said the original acceptance of lab grown terminology had been well-intentioned, but proved to be misplaced.

“At the time, we believed we were acknowledging a commercial reality and extending a constructive hand to a new segment of the industry,” he said, in a special report ahead of the 2025 CIBJO Congress in Paris at the end of October.

“We hoped for a spirit of cooperation, with shared standards, ethics and transparency.”

But he said many in the synthetic diamond sector â€” along with some grading laboratories and major retail chains – took advantage of that inclusive approach.

“In addition, the marketing narrative around synthetic diamonds has been aggressively shaped to position them as the more ethical, sustainable, and conflict-free choice, almost always without substantiation.”

He also called for greater transparency, requiring that all descriptions and marketing of synthetic diamonds reflect the reality of their origin: they are not grown or created in a “laboratory,” but rather are manufactured in industrial facilities through artificial processes.

Source: IDEX