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Last updated: August 13, 2026 · By White Metal Resources Editorial
Quick answer: Iridium is a very hard, brittle, silvery-white platinum-group metal with the symbol Ir and atomic number 77. It is the second-densest naturally occurring metal after osmium, at 22.56 grams per cubic centimeter, and one of the rarest elements in the Earth's crust, with worldwide production of only about 6,800 kilograms in 2023 (USGS and Wikipedia).
It is used industrially in high-performance spark plugs, crucibles for growing single-crystal semiconductors, electrodes for chlorine production, PEM water-electrolyzer anodes, and the radioisotope iridium-192 for medical brachytherapy. There is essentially no retail investment market: no widely traded bullion coin, no meaningful spot ETF and no futures contract on CME Group. Iridium is also not IRA-eligible under IRS rules.
Short on time? The essentials
- Iridium is a platinum-group metal (PGM), symbol Ir, atomic number 77, and the second-densest naturally occurring metal after osmium, with a density of 22.56 grams per cubic centimeter.
- It is one of the rarest elements in the Earth's crust; worldwide production was about 6,800 kilograms in 2023, and only about 7.5 tonnes of iridium is isolated for every 190 tonnes of platinum recovered from ores.
- USGS estimated the annual average iridium price at 4,800 dollars per troy ounce in 2024, up from 1,633.51 dollars in 2020 and after a spike to 5,158.40 dollars in 2021.
- Dominant uses are high-performance spark plugs (including aviation), crucibles for growing oxide single crystals such as sapphire and gadolinium gallium garnet by the Czochralski process, and electrodes for chlorine production in the chloralkali industry.
- Iridium is also the anode catalyst in proton exchange membrane (PEM) water electrolyzers, a component of some OLEDs, and its radioisotope iridium-192 is a workhorse source for medical brachytherapy and industrial gamma radiography.
- There is essentially no retail investment market. No sovereign mint issues an iridium bullion coin at any meaningful scale, no widely traded spot ETF exists, and CME Group has no iridium futures contract; trade is wholesale between refiners, industrial users and specialist bullion houses.
- Iridium is not IRA-eligible under IRS rules; only the four listed metals (gold, silver, platinum, palladium) meeting the fineness thresholds in Internal Revenue Code section 408(m)(3) qualify.
- South Africa, Russia (Norilsk) and Canada (Sudbury) host the world's main iridium-bearing reserves, mostly as a byproduct of platinum and nickel-copper mining.
This page is for readers who came across the word iridium in a spark plug advert, a fuel cell news story, a jewelry hallmark or a cancer treatment description. The next sections cover what the metal is, where it comes from, what it costs and why it is almost impossible to buy as an ordinary investor. Every figure below traces to a primary source cited inline.
What is iridium?
Iridium is a chemical element with the symbol Ir and atomic number 77. It sits in group 9 of the periodic table, between osmium and platinum, and it is one of the six platinum-group metals (PGMs), alongside palladium, platinum, osmium, rhodium and ruthenium.
Wikipedia describes it as "a very hard, brittle, silvery-white transition metal of the platinum group" that is "considered the second-densest naturally occurring metal (after osmium), with a density of 22.56 g/cm3" (source: Wikipedia, Iridium, checked August 2026).
The metal melts at 2,446 degrees Celsius (2,719 kelvin) and boils at 4,130 degrees Celsius. It resists corrosion better than almost any other metal, including all acids and aqua regia at ordinary temperatures. Those three traits (extreme density, very high melting point, near-total corrosion resistance) explain most of what iridium is used for.
Two stable isotopes exist in nature: iridium-191 at 37.3 percent abundance and iridium-193 at 62.7 percent. The neutron-activated radioisotope iridium-192 has a half-life of 73.82 days and drives most of the medical and industrial-radiography uses discussed below.
How rare is iridium?
Iridium is one of the rarest elements in the Earth's crust. Worldwide production of iridium was about 6,800 kilograms, or 6.8 tonnes, in 2023, according to Wikipedia's compilation of trade data (source: Wikipedia, Iridium, checked August 2026).
For scale, worldwide new-mine platinum production ran at about 170,000 kilograms (170 tonnes) in 2024, and palladium at about 190,000 kilograms (190 tonnes), based on USGS estimates (source: USGS Mineral Commodity Summaries 2025, Platinum-Group Metals, checked August 2026). Iridium is roughly 25 times scarcer than platinum on a new-mine basis.
The scarcity has a mineralogical reason. Wikipedia notes that "for every 190 tonnes of platinum obtained from ores, only 7.5 tonnes of iridium is isolated" (source: Wikipedia, Iridium). Iridium is not mined for its own sake at industrial scale; it is a byproduct of platinum and nickel-copper mining.
United States imports for consumption of iridium were about 1,400 kilograms in 2024, roughly one fifth of world production, per USGS (source: USGS Mineral Commodity Summaries 2025, Platinum-Group Metals, checked August 2026). That number gives a sense of how thin the physical market really is.
Where iridium is mined and how it is recovered
Iridium is recovered as a byproduct of primary platinum and nickel-copper deposits, not from dedicated iridium mines. The largest primary PGM reserves sit in the Bushveld igneous complex in South Africa. Other significant sources are the copper-nickel deposits near Norilsk in Russia and the Sudbury Basin in Canada, both associated with ancient impact structures (source: Wikipedia, Iridium, checked August 2026).
Because iridium is a byproduct, its output does not respond quickly to price. If iridium alone rallies but platinum stays weak, mines do not open new capacity, since the platinum revenue still dominates the mine plan. That structural feature is one reason iridium prices can move so sharply on modest demand shifts.
Refining is a chemical process that runs after the primary PGM concentrate is produced. Two common paths to render iridium-bearing material soluble are fusion with sodium peroxide followed by aqua regia extraction, or extraction with a chlorine and hydrochloric acid mixture. Iridium is then separated by precipitating ammonium hexachloroiridate or by liquid-liquid extraction with organic amines.
The refining step is dominated by a small group of specialist companies, including the LBMA-listed platinum-group refiners in South Africa, Europe, Japan and the United States. The refined metal is sold directly to industrial end users and to specialist bullion houses, not to a public exchange.
What iridium is used for
Iridium's uses are almost entirely industrial. The four categories below cover most of its annual consumption.
High-performance and aviation spark plugs
Iridium alloys are used for the centre electrodes of high-performance spark plugs because they resist arc erosion at very high temperatures. Wikipedia notes that "iridium-based spark plugs are particularly used in aviation" (source: Wikipedia, Iridium, checked August 2026). The tips are extremely small (fractions of a milligram of iridium per plug), so the market absorbs many millions of plugs per year using a modest total mass of metal.
Crucibles for single-crystal semiconductor growth
Iridium's high melting point and corrosion resistance make it the material of choice for crucibles used in the Czochralski process, where oxide single crystals are pulled from molten oxide melts at up to 2,100 degrees Celsius. The crystals grown this way include synthetic sapphire, gadolinium gallium garnet (GGG) and yttrium gallium garnet (YGG), which are used in solid-state lasers, LED substrates and specialist optics (source: Wikipedia, Iridium, checked August 2026).
Electrodes for the chloralkali process
The industrial production of chlorine and caustic soda by electrolysis of brine uses dimensionally stable anodes coated with iridium and ruthenium oxides. Iridium-oxide coatings resist the oxidizing environment inside the cell for years, which keeps operating costs manageable in what is a very large-volume chemical process.
Anode catalyst in PEM water electrolyzers
Proton exchange membrane (PEM) water electrolyzers are the technology behind much of the current "green hydrogen" build-out plan. They use iridium as the anode catalyst for the oxygen evolution reaction, with platinum on the cathode side (source: Wikipedia, Polymer electrolyte membrane electrolysis, checked August 2026). Iridium availability is a real constraint on how fast PEM capacity can scale, a point the International Energy Agency has flagged in its hydrogen work.
Iridium-192 for medical brachytherapy and industrial radiography
The radioisotope iridium-192, produced by neutron activation of natural iridium-191, is a workhorse gamma-radiation source. It is one of the two most important sources used in industrial gamma-radiography for non-destructive testing of welds in steel, and a common source in high-dose-rate brachytherapy for prostate, cervical and biliary cancers (source: Wikipedia, Iridium, checked August 2026).
Other uses
Iridium complexes are used as catalysts in the Cativa process for producing acetic acid, in asymmetric hydrogenation for chiral herbicides such as (S)-metolachlor, and in some OLED emitter designs. Historically, a 90 percent platinum and 10 percent iridium alloy was used to construct the International Prototype Meter and Kilogram in 1889, held at the International Bureau of Weights and Measures near Paris (source: Wikipedia, Iridium, checked August 2026).
The iridium price and how the market works
There is no daily public benchmark auction for iridium. USGS publishes an estimated annual average price in its Mineral Commodity Summaries, based on Engelhard unfabricated metal averages sourced from S and P Global Platts Metals Week (source: USGS Mineral Commodity Summaries 2025, Platinum-Group Metals, checked August 2026). Specialist refiners such as Johnson Matthey and Heraeus post reference prices during business hours; those quotes drive most of the wholesale trade.
The USGS series shows how much a thin market can move in a few years. The estimated annual average iridium price rose from 1,633.51 dollars per troy ounce in 2020 to 5,158.40 dollars in 2021, then eased to 4,581.93 dollars in 2022, 4,672.78 dollars in 2023 and back to about 4,800 dollars in 2024.
A 200 percent move in a single year on the annual average is normal in a market whose entire output would fit in the back of a delivery truck. Buyers are almost all industrial firms with signed offtake or reference contracts, and prices are negotiated bilaterally, not shouted across a trading pit.
The worked example below shows how to compute a rough metal value for a small piece of iridium. It uses raw dollars first, then a share, and every number is labeled as an illustration.
Picture a laboratory selling a spent iridium crucible fragment that weighs 100 grams and is essentially pure iridium metal. Assume, illustratively, that the reference price that week is 4,800 dollars per troy ounce, consistent with the USGS 2024 estimated annual average.
- Convert grams to troy ounces: 100 grams divided by 31.1035 grams per troy ounce equals 3.215 troy ounces of iridium content.
- Compute the raw metal reference: 3.215 troy ounces multiplied by 4,800 dollars per troy ounce equals 15,432 dollars of metal value at the illustrative reference price.
- The refiner's offer will sit below this figure, because it includes a refining, assay and margin charge. Actual refiner haircuts on small parcels of pure iridium are qualitatively meaningful, not a few basis points; ask two refiners for a written quote before shipping.
- On a plated or alloyed piece, the metal content must be assayed first; a nominal 100 gram piece may contain far less than 100 grams of iridium once the substrate and coatings are subtracted.
These numbers are illustrative, not quotes from any refiner and not a forecast of future prices. They show how to convert a mass and a reference quote into a rough metal value, not what any given piece is worth on any given day. This is an illustration, not financial advice.
Why there is essentially no retail iridium product
An investor looking for iridium the way they might look for a gold coin or a silver bar will run into several practical walls at once. Each one is enough to keep the retail market small; together they close the door almost entirely.
The list below covers the main reasons.
- No sovereign mint issues an iridium bullion coin at meaningful scale. The US Mint, Royal Canadian Mint, Perth Mint and Royal Mint all produce gold, silver, platinum and palladium bullion coins, but none issues a mainstream iridium bullion coin. A handful of private mints have produced iridium rounds and small bars over the years; those pieces trade in specialist collector channels, not in an active bullion market.
- Iridium is famously difficult to work. Its melting point of 2,446 degrees Celsius and its brittleness at room temperature make it hard to cast, roll or strike. Sovereign mints price in reliable, repeatable production; iridium does not fit that profile at the scale a bullion program requires.
- There is no widely traded spot iridium ETF. The physically backed ETFs that hold platinum and palladium (such as the products from abrdn or Sprott) do not have an iridium counterpart trading with meaningful volume on a major US exchange. Without a liquid vehicle, retail participation stays negligible.
- CME Group has no iridium futures contract. Platinum and palladium each trade as standardized NYMEX futures with a public settlement price. Iridium does not, which removes the public price-discovery anchor a retail bullion market normally relies on.
- Bid-ask spreads on small pieces are wide. With annual world production of about 6.8 tonnes, any specialist bullion dealer who takes a small iridium piece must warehouse it until an industrial buyer needs it. That inventory risk shows up as a wide spread between the buy and the sell side, which crushes a retail investor's round-trip economics.
- Wholesale trade is negotiated, not quoted. Industrial buyers sign offtake contracts with refiners and specialist bullion houses. That is where the metal flows; it is not a place an individual investor can plug into with a small order.
A short summary is that iridium behaves like a specialty industrial input, not like a monetary metal. The retail ecosystem (mint programs, ETFs, futures, dealer sheets) that surrounds gold and silver, and to a lesser extent platinum and palladium, simply does not exist for iridium.
Why iridium is not IRA-eligible
Even if a retail market existed, iridium would not be eligible for a US self-directed individual retirement account. The IRS rule is closed-ended and short.
Internal Revenue Code section 408(m)(3) lists the only four metals allowed in a precious metals IRA: gold, silver, platinum and palladium, each meeting specified fineness thresholds. Iridium, rhodium, osmium and ruthenium are not on that list, and no IRS ruling extends the definition.
Held in a taxable brokerage or a specialist dealer relationship, iridium is a normal collectible or industrial holding subject to standard tax treatment. Held in a retirement account, it would trigger the disallowed-property rules and could deem the account distributed. This is a hard rule with no work-around.
Readers who want the full mechanic of that IRS rule and how it applies to rhodium and iridium specifically can read our companion page: why rhodium and iridium are not IRA-eligible.
Iridium compared with the other platinum-group metals
The table below places iridium alongside the two IRA-eligible white PGMs (platinum and palladium) and its sister metal rhodium, using the same USGS data source where possible. It is a quick reference, not a ranking.
| Feature | Iridium | Platinum | Palladium | Rhodium |
|---|---|---|---|---|
| Symbol / atomic number | Ir / 77 | Pt / 78 | Pd / 46 | Rh / 45 |
| Density (g/cm3) | 22.56 | 21.45 | 12.02 | 12.41 |
| Melting point (deg C) | 2,446 | 1,768 | 1,555 | 1,964 |
| 2024 world mine production (tonnes) | about 6.8 (2023, Wikipedia) | about 170 (USGS 2024e) | about 190 (USGS 2024e) | about 20 to 30 (industry estimates) |
| USGS 2024 avg price (USD/oz t) | 4,800 | 950 | 980 | 4,600 |
| Public daily benchmark | None; specialist refiner quotes only | LBMA Platinum Price twice daily | LBMA Palladium Price twice daily | Johnson Matthey reference; no LBMA fix |
| CME Group futures | None | NYMEX platinum, 50 troy oz | NYMEX palladium, 100 troy oz | None |
| Sovereign bullion coin | No mainstream program | American Platinum Eagle and others | American Palladium Eagle and others | No mainstream program |
| IRA-eligible (IRC 408(m)(3)) | No | Yes at 0.9995 fineness | Yes at 0.9995 fineness | No |
| Dominant end uses | Spark plugs, crucibles, chloralkali electrodes, PEM electrolyzer anodes, Ir-192 medical sources | Autocatalysts, jewelry, industrial catalysts, investment | Autocatalysts, electronics, dental, investment | Autocatalysts (gasoline three-way), glass manufacturing |
Sources: USGS Mineral Commodity Summaries 2025, Platinum-Group Metals; Wikipedia entries for Iridium, Platinum, Palladium and Rhodium; LBMA, About LBMA Daily Auction Prices; CME Group product pages. Checked August 2026. World mine production for rhodium is an industry estimate, not a USGS figure.
Limits and caveats
Everything above describes the iridium market as it stands in August 2026. A few honest caveats belong on a reference page like this one.
- Production and price figures come from published sources. USGS Mineral Commodity Summaries publishes annual averages with a lag; Wikipedia's 2023 production number relies on trade press. Real-time quotes from Johnson Matthey, Heraeus and Umicore differ; the market has no single public tape.
- A retail iridium market could develop. A private mint could launch a coin program, an ETF sponsor could file for a physically backed vehicle, or CME Group could list a futures contract. Any of those would change the picture. None is announced at the time of writing.
- The IRS rule is what it is. Iridium is not in Internal Revenue Code section 408(m)(3). Only Congress can change that list, and no bill on the table proposes it. Anyone selling iridium as a retirement-account investment is misrepresenting the rule.
- Nobody can predict where the iridium price will go. A thin market with mostly industrial demand can move sharply on modest supply or demand shifts. Reading the mechanism helps you understand the quote; it does not turn a quote into a strategy.
- This is not financial advice. A reference page can explain what iridium is and why the retail market barely exists. Choosing whether to hold PGMs at all, and in what form, is a personal decision that belongs with a licensed advisor familiar with your situation.
Iridium questions, answered
What is iridium used for?
Iridium is used mostly in five industrial applications. Those are high-performance and aviation spark plugs, crucibles for growing single-crystal oxides such as sapphire in the Czochralski process, and electrodes for chlorine production in the chloralkali industry. It is also the anode catalyst in proton exchange membrane (PEM) water electrolyzers and the source metal for iridium-192, used in medical brachytherapy and industrial gamma-radiography. Its extreme density, very high melting point and corrosion resistance drive almost all of these applications.
Is iridium the densest metal?
No. Iridium is the second-densest naturally occurring metal, at 22.56 grams per cubic centimeter, according to modern X-ray crystallography measurements. Osmium is slightly denser at 22.59 grams per cubic centimeter. The two values are close enough that older sources sometimes rank them the other way, but the current consensus in reference works is that osmium is first and iridium second.
How rare is iridium?
Iridium is one of the rarest elements in the Earth's crust. Worldwide production was about 6,800 kilograms, or 6.8 tonnes, in 2023 (Wikipedia). For every 190 tonnes of platinum recovered from ores, only about 7.5 tonnes of iridium is isolated. It is roughly 25 times scarcer than platinum on a new-mine basis, and it is recovered as a byproduct of platinum and nickel-copper mining rather than at dedicated iridium mines.
Why can I not buy iridium bullion coins?
No major sovereign mint issues an iridium bullion coin at meaningful scale. Iridium melts at 2,446 degrees Celsius and is brittle at room temperature, which makes it hard to work at the reliability a mint program needs.
There is also no widely traded spot iridium ETF and no CME Group iridium futures contract, so a retail bullion program would lack the standard price-discovery infrastructure. A handful of private mints have produced iridium rounds and small bars in the past; those pieces trade in specialist collector channels, not in an active bullion market.
Can I hold iridium in a self-directed IRA?
No. Internal Revenue Code section 408(m)(3) lists only four metals as eligible for a precious metals IRA: gold, silver, platinum and palladium, each meeting specified fineness thresholds. Iridium, rhodium, osmium and ruthenium are not on that list. Holding iridium inside an IRA would trigger the disallowed-property rules and could deem the account distributed. Our companion page on why rhodium and iridium are not IRA-eligible covers the mechanic in full.
Where does iridium come from?
Iridium is a byproduct of primary platinum and nickel-copper mining. The largest reserves sit in the Bushveld igneous complex in South Africa. Other significant sources are the copper-nickel deposits near Norilsk in Russia and the Sudbury Basin in Canada, both associated with ancient impact structures. Refining is done by a small group of specialist companies in South Africa, Europe, Japan and the United States, and the refined metal is sold to industrial end users through direct contracts.
Why is iridium so important for PEM electrolyzers?
Proton exchange membrane (PEM) water electrolyzers use iridium as the anode catalyst for the oxygen evolution reaction, with platinum on the cathode side (Wikipedia). Iridium is one of the few materials that survives the highly oxidizing environment at the anode over the multi-year operating life the industry needs. The International Energy Agency has flagged iridium availability as a constraint on how fast PEM hydrogen capacity can scale, because global iridium production is only a few tonnes per year.
Is there a daily iridium spot price?
No published exchange auction sets an official daily iridium spot price. USGS publishes an estimated annual average price in Mineral Commodity Summaries, based on Engelhard unfabricated metal averages sourced from S and P Global Platts Metals Week. Specialist refiners such as Johnson Matthey and Heraeus post reference prices during business hours, and those quotes drive most of the wholesale trade. That is why every price figure on this page is labeled as annual and as an estimate.
Sources
- U.S. Geological Survey, Mineral Commodity Summaries 2025, Platinum-Group Metals (annual iridium and platinum data 2020 to 2024; U.S. imports, mine production, world reserves and estimated annual average prices). Checked August 2026.
- Wikipedia, Iridium (density 22.56 g/cm3; melting point 2,446 deg C; worldwide production 6,800 kg in 2023; dominant uses in spark plugs, crucibles for the Czochralski process, chloralkali electrodes; iridium-192 half-life 73.82 days for brachytherapy and industrial radiography). Checked August 2026.
- Wikipedia, Polymer electrolyte membrane electrolysis (iridium as the anode catalyst for the oxygen evolution reaction in PEM electrolyzers; IEA availability constraint). Checked August 2026.
- London Bullion Market Association, About LBMA Daily Auction Prices (twice-daily platinum and palladium benchmarks; no LBMA daily auction exists for iridium or rhodium). Checked August 2026.
- Legal Information Institute, 26 U.S. Code section 408 (defines a precious metals IRA and the eligible metals list at 408(m)(3), which covers gold, silver, platinum and palladium at specified fineness only). Checked August 2026.
- CME Group, Platinum Futures product page (standardized 50 troy oz NYMEX platinum contract, illustrating the exchange-traded infrastructure that iridium does not have). Checked August 2026.
- International Energy Agency, Global Hydrogen Review 2023 (background on PEM electrolyzer scale-up and PGM material intensities). Checked August 2026.
