How Many Red Diamonds Are There? 24 Over One Carat

The public record holds 24 unmodified Fancy red diamonds over one carat. That is the count in a 2025 study by the Gemological Institute of America (GIA), built from auction catalogues and news reports (GIA, Gems & Gemology, Spring 2025). In GIA’s own laboratory data, stones that are mainly red make up only about 0.07% of the more than one million fancy-colour diamonds it has graded. Smaller stones and privately held ones are not listed in any public register, so nobody can give a true world total. Every figure below says what it counts and who published it.

One mine explains why the number is so small. Argyle, in Western Australia, supplied most of the world’s pink and red stones until its last day of mining on 3 November 2020 (Rio Tinto). Below you will find the count by method, the stones that are well documented, where they came from, what they sell for, a calculator, and a short guide to checking any claim yourself.

How many red diamonds are there in the world

There are several honest answers, because researchers count different things. The table shows each measure, what it covers and where it comes from. They are not meant to be added together.

GIA also notes that private stones have passed through its laboratory and other laboratories but are left out of its tables because they are not public knowledge. The “fewer than 30” figure that circulates on trade and retail pages is therefore a rule of thumb. The museum’s 20 to 30 refers to true reds that are mostly small, while GIA’s 24 refers to larger Fancy reds that reached the public record. The two statements measure different things.

For context, GIA’s 2014 review of the Argyle tenders puts all noticeably coloured diamonds at about 0.01% of world diamond production, and calls reds the rarest of that group, with only a handful documented before Argyle (GIA, Gems & Gemology, Winter 2014).

What counts as a red diamond

The answer depends on the grading rule. GIA does not call a diamond red unless the last word of its colour description is “red”. Red also has only one intensity grade, Fancy, unlike pink, which has several, such as Fancy Intense and Fancy Vivid. A purplish red stone is graded Fancy purplish red and is counted as red in the 0.07% figure, but it is not a Fancy red. The historic DeYoung Red, at 5.03 carats, has a darker red-brown colour and does not meet the rule (GIA, 2025).

Chart

Most red diamonds graded by GIA carry no colour modifier

Share of predominantly red diamonds, by GIA colour description; more than one million fancy-colour diamonds studied

Within the predominantly red group, a little over half are plain Fancy red. Most of the rest are modified by purple. Orange and brown modifiers are rare.

The colour is not caused by one trace element in the way boron makes a diamond blue. GIA links it to plastic deformation, a stress-induced change in the crystal lattice that happened under heat and pressure deep in the Earth. In the Winston Red, a 550 nm absorption band tied to that deformation works together with the N3, H4 and H3 nitrogen-related features to give a pure crimson (GIA, 2025; plastic-deformation quote: Diamond World).

Notable red diamonds and what is known about each

These stones have a documented weight and history. The table is not a ranking of every red diamond, and sizes are as reported by the sources named.

GIA describes the Winston Red as the only Fancy red diamond on public exhibit, which makes it the easiest of these stones to see in person.

Where red diamonds come from

Argyle, in the East Kimberley region of Western Australia, is the main source. Rio Tinto says the mine produced more than 90% of the world’s pink diamonds (Rio Tinto, Argyle). Among the 399 Fancy red stones GIA tested for nitrogen, 156 were identified as Argyle stones, and the large unknown remainder probably includes many more (GIA, 2025). Argyle’s ore sits in a lamproite pipe, a volcanic rock that carried diamonds up from the mantle. Explorers found a few alluvial diamonds in the area in the late 1960s, recognised the host rock about a decade later, and had the mine fully running by late 1985 (GIA, 2014).

Other sources are thin. GIA records three of its tested Fancy reds as coming from Minas Gerais in Brazil, and names Santa Elena in Venezuela and marine deposits in Namibia as places that yield similar pink diamonds. The Moussaieff Red was found in Brazil, and GIA considers Venezuela or Brazil the likely home of the Winston Red. Argyle’s output of rough diamond came to more than 865 million carats over 37 years, but only a tiny share was pink or red (International Mining). For a country-by-country view, see our guide to where red diamonds are found, and for the biggest diamonds by weight, our report on the biggest diamond mines.

The Kimberley Process, the body that tracks rough diamond output, lists Australia’s 2024 production as zero carats (Kimberley Process, 2024 summary). The mine that made red diamonds a market has no output to report.

What has happened to the Argyle mine since it closed

Mining at Argyle stopped on 3 November 2020 after 37 years, Rio Tinto said in 2020 that closure would take about five years, followed by monitoring (International Mining), and now says it is on track to finish removing infrastructure, profiling the landform and revegetating in 2026, with about 2,000 hectares to be rehabilitated (Rio Tinto, Argyle closure update). More than 35% of the site works are being delivered by Traditional Owner businesses, according to the company. The site will then be monitored.

The clay-animation video below explains the seven main ways mining changes land, which is the context for closure work at a mine like Argyle.

▶ The seven main environmental impacts of mining, explained in clay animation with satellite maps. · 2:31

Are there any more red diamonds in the world, or are they all found

Some new stones still reach the public, but not from fresh mining at Argyle. Three routes remain. The first is stock that was already cut. Rio Tinto launched its final Beyond Rare tender on 19 September 2025, with 52 lots that included pink, red and violet diamonds from its Australian and Canadian mines. On 1 October 2026 it announced that the Argyle Pink Diamonds brand had passed to the jeweller Boodles, which also acquired the last remaining Argyle pink diamond inventory (Rio Tinto, Argyle releases). Mine-direct supply is therefore over.

The second route is resale. The Argyle Phoenix shows how it works. GIA’s account of the 2013 Argyle tender lists a 1.56 ct Fancy red of that name that set the mine’s highest per-carat price at the time. The stone sold again at Phillips Geneva in May 2024 under the same name and weight, which suggests Rio Tinto first sold it about eleven years before it set an auction record. That corrects a common claim that the stone only came to market in 2024. The third route is a private collection becoming public, as with the Winston Red, which entered a museum in 2023 and went on show in 2025.

New finds elsewhere are possible but unproven in the sources checked. Nothing published shows a second deposit that yields red stones at Argyle’s rate. So “how many are left” has no countdown answer: the count rises only when a hidden stone is graded, sold or shown.

What red diamonds sell for

Public results run from US$926,316 per carat in 1987 to about US$2.7 million per carat in 2024. The table lists the four auction results used for the chart and the calculator. Prices per carat depend heavily on size, hue purity and clarity, so a range from one decade is not a quote for another stone.

Chart

Public red-diamond sales, price per carat against weight

Four auction results; Hancock Red and Heritage per-carat values are calculated from the reported prices

The Argyle Phoenix sold well above its high estimate of US$1.5 million, and Phillips said it set records for both total price and price per carat for a Fancy red (National Jeweler, 15 May 2024). Laurence Graff, founder of Graff Diamonds, bought it (JCK, 20 May 2024). The Christie’s Geneva stone of November 2020 was a purplish red set in a Graff ring, and its result was reported at CHF 2,760,000 (about US$2.77 million in total), equal to US$2.64 million per carat (Jewellery Outlook). The Cape Town Diamond Museum says a natural Fancy red rarely starts below US$100,000 for a stone above 0.20 ct (Cape Town Diamond Museum). For the factors that move a price, read our red diamond price range guide. For another rare stone priced from sparse sales, see our painite price per carat page.

Estimate the value of a red diamond

The calculator below multiplies your stone’s weight by a per-carat price you choose, adds a premium and fixed costs, and shows the same weight at the 1987 Hancock Red rate and the 2024 Argyle Phoenix rate. It is a way to see the spread, not an appraisal.

How red diamonds compare with the rest of the rough diamond market

Ordinary rough diamond production is a volume business. The Kimberley Process counted 107.9 million carats worth US$9.53 billion in 2024, an average of US$88.35 per carat, compared with 112.1 million carats worth US$12.89 billion in 2023, or US$115.04 per carat (Kimberley Process, 2024 summary; 2023 summary). Output fell by 3.7% in volume and 26% in value. Russia led in 2024 with 37.3 million carats, followed by Botswana (18.1 million), Angola (14.0 million) and Canada (13.3 million). Among producers above two million carats, Namibia had the highest average value at US$416.88 per carat, against US$124.03 for South Africa and US$10.84 for the DRC.

Chart

Average rough value per carat, 2024

US dollars per carat, producers above two million carats

Chart

Rough diamond output rose in some countries and fell in others

Production by volume, million carats, eight producers listed by the Kimberley Process

Set against that, the Argyle Phoenix fetched about US$2.7 million per carat as a polished stone, roughly 30,000 times the 2024 average for rough. Treat that ratio as an illustration only. It compares a single cut stone with the average of all rough output, which includes industrial-grade material, and rough weighs more than the polished stone it yields. The Kimberley Process does not break out coloured or red diamonds, and it publishes each year’s figures about six months after the year ends (Kimberley Process, public statistics). The 2025 summary is now posted: 98.8 million carats worth US$9.23 billion, an average of US$93.43 per carat, with Russia at 31.5 million, Botswana 15.5 million, Angola 15.2 million and Canada 14.1 million (Kimberley Process, 2025 summary). Australia again reported zero carats.

How to check a red diamond claim yourself

Any count, including this page’s, is a snapshot. The following checks tell you what a claim is really based on.

Infographic

Check a red diamond claim in 5 steps

1. 1Get the lab reportLook for a GIA grade of Fancy red or a description ending in red.
2. 2Read the GIA archiveSearch Gems & Gemology for studies on the stone.
3. 3Search auction recordsLook for lot notes and results from Christie’s, Sotheby’s, Phillips and Heritage.
4. 4Check provenanceMatch any Argyle claim to a Rio Tinto tender year.
5. 5Keep totals separateUse Kimberley Process tables for rough output, not colour counts.

1. Ask for the laboratory report. A GIA report that grades a stone Fancy red, or a colour description ending in “red”, is the basis of GIA’s own counts.
2. Check the Gems & Gemology archive. GIA publishes studies and lab notes on notable reds, such as the Spring 2025 paper on the Winston Red.
3. Search auction archives. Christie’s, Sotheby’s, Phillips and Heritage post lot notes and results; a new entry for a stone over a carat is the clearest sign the public record has grown.
4. Check provenance. Argyle’s pink and red stones were sold through annual invitation-only tenders (the 30th was held in 2014) and are catalogued by tender, so the tender year is a useful anchor.
5. Use the Kimberley Process tables only for total rough output, not for colour. They show whether the supply backdrop is changing.

Can satellite screening help find the next source of red diamonds

Not directly. Red colour forms by deformation inside a diamond crystal, and it cannot be seen from orbit. What satellites can do is screen terrain for the kind of rock and structure that hosts diamonds, such as kimberlite and lamproite pipes, so that a field team knows where to look first. Argyle’s own history shows how slow that work is: about sixteen years passed from the first alluvial finds to a fully operating mine. A satellite result is a lead for follow-up and sits well ahead of any resource estimate. It cannot show whether a pipe contains pink or red stones.

Farmonaut’s satellite mineral detection covers diamonds among its listed targets, and you can read how the method works in our guide to satellite-based mineral detection. The video below explains what AI-assisted exploration does and does not do.

▶ What AI-assisted mineral exploration does, where it fails and how to check any claim. · 4:37

Frequently asked questions

How many red diamonds are there in the world?

GIA’s 2025 study lists 24 unmodified Fancy red diamonds over one carat in the public record. Counting smaller and private stones is not possible from public data, though red makes up about 0.07% of the coloured diamonds GIA has graded.

How many red diamonds are left in the world?

There is no fixed original supply to count down from. The documented stones stay in the record, and the number changes when a hidden stone is graded, auctioned or exhibited. Argyle stopped mining on 3 November 2020 and Rio Tinto has passed its last Argyle pink inventory to Boodles.

Are there any more red diamonds in the world?

Yes, but they come from resales, estates and museum donations rather than new mining at Argyle. The Argyle Phoenix, first offered in 2013 and re-sold in 2024, is one example; the Winston Red, shown at the Smithsonian since 1 April 2025, is another.

How many red diamonds have been found in total?

Nobody publishes this. GIA tested 399 Fancy red diamonds for nitrogen, but that is a laboratory sample, not a census, and the stones that never reached a laboratory are unknown.

How many natural red diamonds are there?

The Cape Town Diamond Museum puts “true” natural reds at about 20 to 30, mostly under half a carat. GIA counts 24 Fancy reds over one carat in the public record. These use different rules, so they do not conflict.

Where are red diamonds found?

Mostly at Argyle in Western Australia, which Rio Tinto says supplied more than 90% of the world’s pink diamonds. Smaller numbers come from Brazil, with Venezuela and Namibia named by GIA as sources of similar pink stones.

How much is a red diamond worth?

Public sales range from US$926,316 per carat for the Hancock Red in 1987 to about US$2.7 million per carat for the Argyle Phoenix in 2024. Use the calculator above to see what your weight gives at each rate.

Is the Argyle mine still open?

No. Mining ended on 3 November 2020, and Rio Tinto says it is on track to finish removing infrastructure, reshaping the land and revegetating in 2026, after which the site will be monitored.

Why is a red diamond different from a pink one?

The colour comes from the same type of lattice deformation, but red is darker and more saturated, and GIA gives it a single grade, Fancy, while pink has several grades. GIA calls red the rarer of the two.

Can satellite imagery find red diamonds?

No. Satellites cannot see a diamond’s colour. They can help screen areas for diamond-bearing rock before a field team goes in, and only drilling and grading show what a pipe holds.

Where can I get a satellite-based site analysis?

Map an area of interest at the Farmonaut mining query form to request a quote, or reach the team through Contact Us.