Iridium powder is refined iridium (Ir, element 77, CAS 7439-88-5) reduced to a fine metallic particulate, one of ten iridium product pages in DailyPlatinum's directory of PGM products, shipped under an ASTM specification that documents two purity grades. Buyers most often ask what separates powder from the metal's other refined forms, and the sections below answer that with the purity ladder, the manufacturing route, the dominant applications and the price basis, before pointing to where the form is bought.
What Is Iridium Powder?#
Iridium powder is a fine, dense particulate form of iridium (Ir, element 77, CAS 7439-88-5), distinct from iridium sponge, the coarser and more porous primary output of the same refining step. Both forms come from the same hydrogen-reduction stage of refining iridium (Ir), element 77, but sponge is the porous, as-reduced structure while powder is milled or precipitated finer and denser, the same distinction Umicore draws between sponge and powder across the platinum group metals. Iridium powder also carries the element's defining mechanical trait: iridium is so brittle that its heat-affected zone cracks during welding, per Wikipedia's iridium entry, so pressed and sintered powder, not casting or machining, is how solid iridium parts are actually made. That brittleness, paired with a melting point of 2,446°C, is why the manufacturing route below relies on powder metallurgy rather than conventional metalworking.
Iridium Powder Purity Grades and Specifications#
Iridium powder ships in two documented purity grades, 99.80% and 99.90%, under ASTM International's B671 standard, the specification covering refined iridium as sponge and powder. Grade 99.80 carries the designation UNS P06100; Grade 99.90 is ASTM B671's higher tier. Neither grade is written as a bare percentage: each belongs to a named standard, and total permitted impurities scale directly with the purity figure, exactly 2,000 parts per million at 99.80% and 1,000 parts per million at 99.90%.
| Grade | Max total impurities | Standard |
|---|---|---|
| 99.80% (UNS P06100) | 2,000 ppm | ASTM B671 |
| 99.90% | 1,000 ppm | ASTM B671 |
ASTM B671 does not publish a particle-size or mesh specification for iridium powder; buyers needing a specific particle-size distribution state it directly in their purchase specification.
Iridium powder's two ASTM grades sit below its own sponge form on the purity ladder, since Umicore lists a 99.95% minimum for refined iridium sponge, shown against use below.
| Form | Documented purity | Governing standard | Primary use |
|---|---|---|---|
| Iridium powder | 99.80% to 99.90% | ASTM B671 | Powder-metallurgy feedstock, catalyst precursor |
| Iridium sponge | 99.95% minimum | Umicore refinery specification (no dedicated ASTM iridium-sponge grade beyond B671) | Primary refinery output; further fabrication feedstock |
How Iridium Powder Is Manufactured#
Iridium powder is made by dissolving iridium-bearing refinery residues, converting the metal to iridium chloride, then reducing that salt with hydrogen gas. The route runs through three steps documented for iridium's refining stage, the last stage of the flowsheet after platinum, palladium, rhodium and ruthenium have already been separated out.
- Dissolve the iridium-bearing residue, either by fusing it with sodium peroxide and extracting the resulting glass in aqua regia, or by treating it directly with chlorine gas in hydrochloric acid.
- Convert the dissolved iridium to iridium(III) chloride, the same salt sold commercially as a starting material for iridium electroplating and catalyst synthesis.
- Reduce the iridium chloride salt with hydrogen gas, which yields the metal as either powder or sponge, depending on the precipitation and reduction conditions used.
Rhodium and iridium sit at the end of every major refinery flowsheet, processed only after ruthenium is distilled off, one reason minor-PGM powder carries a fabrication premium beyond the contained metal value, covered under price basis below.
What Is Iridium Powder Used For?#
Iridium powder's primary use is as the feedstock for powder-metallurgy fabrication of solid iridium components, because iridium's brittleness and 2,446°C melting point rule out casting or conventional machining for finished parts. Two named processes account for most of that demand.
- Powder-metallurgy fabrication: pressed and sintered iridium powder becomes the stock later drawn into iridium wire, rolled into iridium foil, or hot-pressed into iridium crucibles for oxide crystal growth, since iridium tolerates temperatures above 2,000°C in an oxidizing atmosphere with no contamination to the melt, according to Heraeus.
- Catalyst manufacture: refiners redissolve iridium powder or its chloride precursor to make iridium-based catalysts, including the iridium catalyst used in the Cativa process for acetic acid production, which displaced the older rhodium-catalyzed Monsanto process in several major plants, per Johnson Matthey's PGM Market Report.
Iridium Powder Price Basis#
The price of iridium powder is the iridium metal value at order time, plus a fabrication premium, never a single published catalog number, because the premium moves with grade, dimension and order quantity.
Iridium Powder price = (iridium spot price per troy ounce / 31.1034768) x weight in grams
+ fabrication premium (form, dimension, purity grade, order quantity)
The metal-value leg tracks the iridium price today at order time, and no premium percentage is stated here because no sourced figure for this exact form exists in DailyPlatinum's facts ledger. Buyers converting between units can check the metal value on the iridium price per gram or iridium price per kilogram pages, since fabricators typically price an order against one of those denominations rather than the troy ounce.
Handling Finely Divided Iridium#
No source reviewed for this site documents finely divided iridium as pyrophoric or unusually air-reactive, whether in sponge, black, powder or nanoparticle form. That absence is not a safety certification: handlers of any fine metal powder, including iridium black, still avoid dust generation, ignition sources and inhalation, as general fine-powder practice rather than a documented iridium-specific hazard.
Where to Buy Iridium Powder and Supplier Types#
Iridium powder is sold by refiner-fabricators, scientific-instrument suppliers and specialty metal distributors, each pricing against the live iridium value plus their own fabrication premium. Refiner-fabricators such as Johnson Matthey and Heraeus supply bulk and industrial-grade material alongside their sponge and wrought-form output, while scientific-instrument suppliers list gram-scale packs to laboratories, the pattern across the commercial listings that dominate search results for this form. Specialty metal distributors sit between the two, carrying mid-volume quantities for fabricators not buying refinery-scale lots.
Where Iridium Powder Content Stops: Jewelry Retail and Converter Repair#
This page covers iridium powder as an industrial and laboratory material, not as jewelry alloying stock or catalytic-converter repair content. Iridium plays essentially no role in mainstream jewelry alloys or autocatalyst substrates, so ring-shopping guidance or converter-scrap valuation belongs on this site's platinum jewelry and scrap-converter coverage, not this product page.
Other Iridium Product Forms#
Iridium is also sold as wire, foil and crucibles, each drawn or fabricated from the same refined powder or sponge feedstock described above.
- Iridium wire: drawn stock for thermocouples, electrodes and spark-plug tips
- Iridium foil: rolled sheet stock for laboratory ware and electrodes
- Iridium crucibles: hot-pressed vessels for Czochralski oxide-crystal growth
Other platinum group metals ship as powder too, on their own dedicated pages: platinum powder, palladium powder and rhodium powder, each specified against its own metal-specific standard.
Iridium Price and Market#
Iridium's live spot price and supply and demand balance live on their own pages, alongside the case for holding the metal as an investment. South Africa supplies more than 80% of world primary iridium output, per the International Platinum Group Metals Association, the concentration behind price behavior tracked on the iridium market and the iridium investment page.
Iridium Powder FAQ#
What is the cost of 1 gram of iridium?#
The cost of 1 gram of iridium tracks the live spot market rather than a fixed figure printed on this page. See iridium price today for the current value.
What is iridium commonly used for?#
Iridium is commonly used for spark-plug electrode tips, crucibles for growing oxide crystals, and as a catalyst in the Cativa acetic-acid process, drawing on its high melting point and chemical resistance. A fuller identity and use profile sits on the iridium (Ir), element 77 page.
How much is 1 lb of iridium worth?#
The value of 1 lb of iridium scales directly from its live per-ounce or per-gram spot price, so no fixed figure is stated here. Convert the current value on iridium price today.
Is iridium used in nukes?#
No documented use of iridium in nuclear weapons appears in the sources reviewed for this site. Iridium's one notable radioactive application is the isotope iridium-192, a gamma-emitting source with a 73.8-day half-life used in industrial radiography and high-dose-rate cancer brachytherapy, unrelated to weapons.
Is iridium harmful to humans?#
No sourced hazard classification for bulk or finely divided iridium metal appears in the reference sources checked for this page; see handling finely divided iridium above for the case of iridium powder, sponge and black.