De Beers worked by controlling how many diamonds the world was allowed to see, buying or blocking every rival supplier and then using advertising to make a diamond feel like a necessity, a structure now cracking under lab-grown stones and new producers. A single hole in the ground in South Africa turned into a global price on romance. The company built around it came to shape a market the video puts at between $89 billion and $100 billion a year in diamond jewelry sales, and it decided what millions of couples believe a proposal is supposed to cost.
The story below follows how the system was built, who fought it and who beat it, and why it is breaking apart now. It touches on a founder’s death, conflict diamonds, sanctions and an antitrust plea, so it is told as the video tells it.
Watch the full video here, or skip to the breakdown below.
The 10 chapters at a glance
- The hole that started it all (3:44)
- Buying every exit (8:19)
- The slogan that rewired a ritual (16:42)
- The country the cartel built (26:13)
- The law finally catches up (33:26)
- Blood in the ground (40:48)
- What’s actually in the box (46:11)
- The long way to the store (50:48)
- The mine that made pink famous (55:11)
- Grown, not dug (1:00:00)
1. The hole that started it all
In 1871 prospectors found diamonds on a farm called Vooruitzigt in what is now South Africa. Thousands of independent diggers staked claims a few meters wide and dug straight down, and the site became the Kimberley Mine, later called the Big Hole. Between 1871 and 1914, as many as fifty thousand miners pulled more than twenty-two million tons of earth out of it, almost all by hand.
A young British immigrant named Cecil Rhodes noticed that a claim owner running short of money would eventually sell to whoever could outlast them. He raised capital in London, bought claim after claim and folded them into De Beers Consolidated Mines in 1888. The biggest piece of ground belonged to Barney Barnato, a former East End street trader who had arrived in South Africa in 1873 with a crate of cigars. Barnato’s shareholders blocked Rhodes’ merger in court, so Rhodes raised enough capital to buy Barnato out anyway. Barnato died in 1897 after going overboard from the SS Scot, and the video notes that nobody has fully settled what happened. By 1902 De Beers controlled about ninety percent of the world’s rough diamond production.
Diamonds are not actually rare in the earth’s crust. They form constantly deep underground and are pushed toward the surface through volcanic channels called kimberlite pipes, found across southern Africa, Siberia, Western Australia, Canada and the Democratic Republic of Congo. Once De Beers held a critical mass of the productive ones, it controlled the story about how much of that rock existed. Edward Jay Epstein’s 1982 Atlantic investigation noted that diamonds resell for a fraction of what people paid, because no real open resale market ever existed.
A fortune built on a hole in the ground could survive the digging, and managing what the world believed about it was the harder job.
2. Buying every exit
Owning mines was only step one. Producers outside De Beers could still sell rough stones on the open market and undercut the price, so the company built the Central Selling Organisation, later renamed the Diamond Trading Company. It bought rough stones from producers around the world, including mines De Beers did not own. Independent miners could sell through its single channel at its price, or go it alone and risk De Beers dumping stockpiled diamonds to crash the price of their stones.
In the early 1980s Zaire, now the Democratic Republic of Congo, broke away and began selling directly to merchants in Antwerp through a state company called Sozacom. A speculative bubble in polished stones then collided with a spike in U.S. interest rates, rough sales collapsed by more than half in a year, and De Beers doubled its own stockpile while the rest of the trade sold. Zaire’s independent exports had collapsed by the mid-1980s. At its peak De Beers controlled somewhere between eighty and eighty-five percent of the rough diamond trade.
Harvard’s Debora Spar called it the most successful and longest-lasting cartel in the modern global economy, a group of producers controlling supply together instead of competing on price. It held because each big producer calculated that staying inside paid better than triggering a price war. Inside the trade the mechanism was the sight: ten times a year, selected buyers called sightholders were handed a sealed box of rough stones at a set price, with no negotiation. Refusing could cost a buyer their place on the list.
Namibia took a different route, setting up a fifty-fifty joint venture with De Beers in 2007. At the retail end, Signet Jewelers owns Kay, Zales, Jared and Blue Nile, so brands that look like rivals report to one $6.7 billion company.
Every exit gets bought, blocked or absorbed before it becomes a real alternative.
3. The slogan that rewired a ritual
Diamond sales in the United States stayed sluggish through the 1930s, and diamonds were not seen as essential to getting married. The company hired the advertising agency N.W. Ayer, and a later internal planning document called the job a problem in mass psychology, aiming to make the engagement ring what it termed a psychological necessity for roughly seventy million Americans. Because a diamond has no emotional pull in a display case, the agency skipped carats and attached the stone to permanent love.
It placed diamonds on Hollywood actresses, got a 1940 film retitled from Diamonds Are Dangerous to Adventures in Diamonds, and fed newspapers planted items presenting engagement rings as a time-honored tradition. Then a copywriter named Frances Gerety wrote four words, reportedly almost an afterthought: A Diamond Is Forever. In 1940 roughly ten percent of American brides got a diamond ring. Four decades later it was around eighty percent. The campaign also suggested a month’s salary, later two months’ salary, and Advertising Age ranked the slogan the top of the twentieth century in 1999.
The same playbook ran in Japan from the 1960s, when fewer than five percent of brides received a diamond ring, and within two decades it was sixty percent. A study by economists Andrew Francis-Tan and Hugo Mialon of more than three thousand married Americans found that men who spent two to four thousand dollars on a ring carried a divorce hazard 1.3 times higher than men who spent under two thousand, and that a larger guest list and a honeymoon predicted stability.
There was a second job for the slogan: if a diamond is forever, it is not resold, so De Beers never had to compete with its own past sales. Today the average U.S. engagement ring costs $5,200, down from $6,000 in 2021, and roughly one in three engagement rings sold in the United States goes through a Signet store.
A diamond can be meaningful without being a good investment, and those are different kinds of value.
4. The country the cartel built
Before the next chapter, picture the scale. Workers comb 250 tons of crushed rock a night and may find one carat. The largest gem-quality rough diamond, the 3,106-carat Cullinan, came out of South Africa in 1905. Siberia’s Mir mine, discovered in 1955, reached about 1,200 meters across and more than 525 meters deep. Its operator, Russia’s Alrosa, out-produced De Beers in 2025 with 29.7 million carats against 21.7 million.
Most countries that dealt with De Beers lost. Botswana did not. At independence in 1966 it was one of the poorest countries on earth, with about twelve kilometers of paved road, fewer than two dozen university graduates and almost half its budget from British aid. A year later geologists found diamonds at Orapa, and the government pushed for a direct ownership stake, creating Debswana, still a fifty-fifty partnership with De Beers. In 1987 Botswana swapped a stockpile for just over five percent of De Beers itself, later around ten percent.
From 1965 to 1995 Botswana posted the fastest sustained growth of any country. Economists Daron Acemoglu, Simon Johnson and James Robinson credited strong institutions, not the diamonds, meaning laws, courts and limits on what leaders could grab. Their 2001 paper traced part of this to the local Tswana political system. Diamond money flowed through transparent government channels, unlike in Angola, Sierra Leone and Nigeria.
It still has problems, including about 28 percent unemployment in early 2024 and heavy dependence on one commodity, which its Vision 2036 plan aims to reduce. A ten-year agreement signed in 2025 extends Debswana’s licenses through 2054 and gives Botswana’s Okavango Diamond Company a share of rough output to sell outside the De Beers channel: thirty percent for five years, then forty. It also committed roughly $75 million to a local development fund.
Ownership explains the gap: who held a piece of the pipe and what that ownership funded.
5. The law finally catches up
The U.S. Department of Justice filed an antitrust case against De Beers in 1945, driven less by ring prices than by wartime worry over industrial diamonds used in weapons production. It was dismissed in 1948 on jurisdictional grounds, and the company kept its executives out of American courtrooms and ran its buying through European entities for decades. A 1994 indictment over industrial diamond price-fixing stalled because you cannot prosecute a company that will not walk through the door.
In 2004 De Beers Centenary AG submitted to U.S. jurisdiction and pleaded guilty to conspiring to raise industrial diamond prices, paying a $10 million fine. Civil suits from consumers and jewelers settled at close to $295 million, with about $130 million earmarked for consumers, and De Beers accepted an injunction against monopolizing rough supply. By the turn of the millennium its share had slid to around two-thirds, and after a review with Bain it adopted a Supplier of Choice strategy, trying to own a smaller, better-marketed pond.
By 2021 its share was roughly twenty-five percent, close to Alrosa’s. Russia’s 2022 invasion of Ukraine led the U.S. to sanction Alrosa and the G7 and European Union to restrict Russian-origin diamonds, though a rough Russian stone cut and polished in India could legally re-enter Western markets labeled by where it was processed. Alrosa’s output fell about 4.6 percent in 2024 and it reportedly stockpiled stones, the old De Beers tactic with the roles reversed.
Anglo American paid close to $13 billion in 2011 to take De Beers from the Oppenheimer family, and by late 2025 had written it down to around $2.3 billion. It was reportedly in talks to sell a majority stake to a group led by a former De Beers chief executive for roughly $1 billion. Its 2025 results showed a $511 million EBITDA loss.
The pitch outlasted the balance sheet it was built to protect.
6. Blood in the ground
Through the 1990s, rebel factions in Angola and Sierra Leone financed weapons by selling rough diamonds outside any regulated channel, mined with forced labor and smuggled to cutting centers like Antwerp. The stones became known as blood diamonds or conflict diamonds. A United Nations investigation led by Canadian ambassador Robert Fowler, published in March 2000, documented that the rebel group UNITA generated roughly $3.72 billion from diamonds between 1992 and 1998. The report also stated that De Beers spent about $500 million buying Angolan diamonds in 1992, while its public position was that it avoided conflict stones.
Producers, the industry and the United Nations set up the Kimberley Process Certification Scheme in 2003 to certify rough diamonds as conflict-free before they cross borders. Global Witness, a founding member, withdrew in 2011, arguing the scheme had too many gaps. It counted a stone as a conflict diamond only if the violence was tied to a rebel group, so state-sanctioned violence fell outside the definition. The scheme also runs on consensus, so one state can block action against itself, and it has no independent body monitoring compliance.
One evaluation found conflict diamonds fell from roughly fifteen percent of global sales in the 1990s to about 0.4 percent by 2009, though that headline overstates the result for the same reasons. Canada tried another route, marketing stones from the Ekati mine (first commercial diamonds in 1998) and Diavik (2003) around environmental standards and traceability, with some stones laser-inscribed with a maple leaf. It became the third-largest producer by volume by 2006.
A certificate tells you a stone crossed a border with paperwork. It does not verify every mile before that.
7. What’s actually in the box
Every certified diamond is graded on four Cs: carat, color, clarity and cut. Only carat, a unit of weight equal to 200 milligrams, is a fixed physical fact. Color runs from D, completely colorless, toward Z, where tint becomes visible, judged against reference stones under controlled light. Clarity is graded under ten-power magnification for inclusions and blemishes. Cut is the most mathematically grounded, based on how well proportions route light out the top, yet a trained person still applies a scoring system. The major labs, particularly the Gemological Institute of America, train graders rigorously, but two labs can grade the same stone slightly differently.
Small movements across those judgments swing the price enormously. University of Kentucky economists Frank Scott and Aaron Yelowitz found in 2010 that a half-carat diamond sold for about eighteen percent more than one weighing 0.49 carats, and a one-carat stone carried a five to ten percent premium over 0.99, differences invisible to the eye. They argued it was mostly signaling.
In 2005 a Beverly Hills dealer named Max Pincione sued, alleging a wholesaler had paid GIA lab employees to inflate grades on stones before they reached him. GIA’s own investigation confirmed lab workers had improperly contacted clients and adjusted outcomes for a price, and the lab fired four graders and its director.
The paperwork is only as honest as the person who signed it.
8. The long way to the store
Follow one stone. A half-carat rough diamond sold through a sight almost always heads to Surat, India, where roughly ninety percent of the world’s diamonds by piece count are cut and polished. From there it moves into trading. For most of the twentieth century that meant Antwerp, but in 2021 the United Arab Emirates overtook it as the leading rough trading hub, with Dubai handling more than $22.8 billion of rough stones that year.
Each step adds margin, and the biggest comes at the end. A traditional jeweler uses keystone pricing, roughly doubling the wholesale cost, while online retailers push that closer to ten or twenty percent. There has never been a public price index for diamonds like those for gold or oil, so buyers negotiate against a number nobody outside the trade can verify.
Tilburg University economists Luc Renneboog and Christophe Spaenjers built an index from auction sales between 1999 and 2010 and found white diamonds returned about 6.4 percent a year in real terms and rare colored diamonds about 2.9 percent, both outperforming stocks. But gem returns moved with stock returns, so they concluded diamond prices track general wealth and luxury spending.
That is a demand curve driven by fashion and disposable income, dressed up in a story about geological rarity.
9. The mine that made pink famous
The Argyle mine in Western Australia, run by Rio Tinto, opened in December 1985. At its 1994 peak it pulled about 42 million carats a year, at times the largest mine on earth by volume. In the 1990s Rio Tinto pulled Argyle out of the De Beers system and sold its own diamonds. Unlike Zaire, it had scale and a unique product: pink and red stones nobody else had, getting their color from a distortion in the crystal structure. Argyle produced more than ninety percent of the world’s pink diamonds.
Rio Tinto ran an invitation-only Pink Diamonds Tender for decades, with the 2016 tender the highest-grossing in its twenty-year history and the final 2020 and 2021 tenders setting further records. Mining stopped on November 3, 2020, after 37 years and roughly 865 million carats. That is one of the only cases in the trade where geology alone set the rarity.
Economists Kyle Bagwell and B. Douglas Bernheim showed in 1996 how a good can sell better because it costs more, when price signals the buyer’s wealth. A seller with market power then has reason to keep prices high on purpose, which describes much of the diamond trade. Elsewhere that premium is evaporating: wholesale lab-grown diamond prices have collapsed 96 percent since 2018, falling another 26 percent in 2025.
The mine simply ran out, and no pricing decision can replace it.
10. Grown, not dug
A diamond is crystallized carbon in a specific lattice, and nothing requires it to form underground over a billion years. Chemist Tracy Hall produced the first reproducible synthetic diamonds on December 16, 1954, at General Electric. Its own division Element Six has made lab-grown diamonds for industrial use since the 1950s, and the company chose for a long time not to sell gem-quality ones, since that would undercut its scarcity story.
There are two methods. HPHT uses a press at 1,300 to 1,600 degrees Celsius and extreme pressure, growing a diamond over days to weeks. CVD grows carbon atoms from gas in a vacuum chamber at 900 to 1,200 degrees Celsius over three to four weeks. Both give a stone chemically and optically identical to a mined one, which labs can distinguish only with specialist equipment. The company now sells that equipment itself, under names such as DiamondSure and DiamondView.
Lab-grown stones were about five percent of U.S. engagement ring purchases in 2019 and passed forty-five percent five years later. A one-carat lab-grown diamond that retailed near $3,410 in 2020 sold for $750 to $1,000 by 2025, while a natural one-carat stone fell from roughly $6,000 in 2021 to around $4,200 in 2025. It cut production by roughly twenty percent from 2023 levels, yet revenue fell from about $2.8 billion in the first half of 2023 to around $2.2 billion a year later, and by late 2024 it held close to $2 billion of unsold rough inventory, the biggest stockpile since 2008.
A 2025 study in Commodities by Ingo Wolf and Martin Užík found diamonds carry meaningfully higher volatility than comparable hard assets, weakening the safe-haven case. Lightbox, launched in 2018, sells lab-grown stones at around $800 a carat, and in May 2021 Pandora said it would stop selling mined diamonds.
No stockpile strategy works against a product that can be grown again next month.
Who writes the story
For a hundred years a company built out of one South African hole decided how many diamonds the world was allowed to see, and paid an advertising agency to make a boardroom decision look like a law of nature. Some scarcity here was real and fair: Botswana insisted on ownership instead of a royalty check, and Argyle’s pinks are scarce because a single mine closed.
The lesson reaches beyond diamonds. Any market where one party controls both the supply and the story about that supply can hold a price steady for generations, until a second source nobody can buy out, stockpile or out-market shows up and the whole thing corrects at once.
FAQ
How did De Beers control the diamond market?
It bought mines, then ran the Central Selling Organisation, which purchased rough diamonds from producers worldwide. Producers who stayed outside risked De Beers dumping stockpiled stones to crash their prices. At its peak it controlled eighty to eighty-five percent of the rough trade.
What does ‘A Diamond Is Forever’ mean for ring prices?
The slogan by N.W. Ayer copywriter Frances Gerety helped lift diamond ring ownership among U.S. brides from about ten percent in 1940 to around eighty percent four decades later, and the campaign promoted spending a month’s or two months’ salary.
Was De Beers ever convicted of price-fixing?
In 2004 De Beers Centenary AG pleaded guilty in the U.S. to conspiring to raise industrial diamond prices and paid a $10 million fine. Related civil suits settled at close to $295 million.
Why did Botswana succeed with diamonds?
It negotiated direct ownership through Debswana, a fifty-fifty venture with De Beers, and economists credit strong institutions that limited what leaders could take.
Are lab-grown diamonds the same as natural diamonds?
Chemically, physically and optically they are identical. Labs can tell them apart only with specialist equipment that detects microscopic growth patterns.
Are diamonds a good investment?
The video says no: diamonds resell for a fraction of the price paid, and a 2025 study found they carry higher volatility than comparable hard assets. A few rare colored stones are the exception.
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