Costliest Metal in the World: Iridium, Rhodium, Gold

The costliest metal in the world that trades openly is iridium, at €309.25 per gram on Umicore’s price list on 26 October 2026, with rhodium close behind at €288.05 per gram (Umicore Precious Metals Management). Gold was €127.79 per gram the same day, so both metals cost more than twice as much as gold, weight for weight. Kitco’s separate rhodium quote was a bid of US$8,625 per troy ounce, about US$277 per gram (Kitco, 26 October 2026).

The order at the top is not fixed: USGS annual averages show rhodium far above iridium from 2021 to 2023, just below it in 2024, above it again in the 2025 estimate, and iridium ahead of it on Umicore’s board today. This page ranks the metals per gram on one source and one date, explains why the two leaders cost so much, compares rhodium with gold and with diamonds, and gives a calculator that turns any quote into the cost of your order. It is written for consultants and mine owners who need to price platinum-group metals (PGMs) found with nickel, copper or platinum ore.

Costliest metals ranked per gram

All six rows below come from one price list, Umicore’s, taken on the same day, so the units and the exchange rate are the same for every metal. To get euros per troy ounce, multiply the per-gram price by 31.1035. A troy ounce is the unit used for precious metals and holds 31.1035 grams.

Chart

Metal prices per gram on one list

Euros per gram, Umicore Precious Metals Management, 26 October 2026

Silver, at €1,811.40 per kilogram (about €1.81 per gram) on the same list, is shown in the chart for scale. Osmium, the seventh platinum-group metal, has no public price board, so it cannot be ranked here. These are the metals with a public daily price; a metal with no public price (for example a few grams of a lab-made isotope) cannot be ranked fairly.

Why iridium and rhodium cost so much

Both metals are tiny by-products. The Royal Society of Chemistry (RSC) says world rhodium production is about 30 tonnes a year, taken as a by-product of nickel and copper refining, and that about 80% of it goes into car catalytic converters, where it reduces nitrogen oxides (RSC, rhodium). For iridium the RSC puts output at only about 3 tonnes a year, with uses in spark-plug electrodes and corrosion-proof alloys (RSC, iridium). For scale, USGS puts world platinum mine output at about 170 tonnes and palladium at about 190 tonnes in 2025 (USGS, Mineral Commodity Summaries 2026).

Three features keep prices high and jumpy:

• No mine of their own. Output follows platinum and nickel decisions, so a price rise cannot bring new rhodium or iridium to market quickly.
• Narrow supply. South Africa and Russia are the top two producers on the RSC’s supply-risk table for rhodium, and the Bushveld Complex in South Africa holds the largest PGM resources (USGS).
• A thin market. Kitco notes that rhodium has no exchange-traded futures market and trades dealer to dealer, so quotes can gap sharply between updates.

Rhodium vs gold price per gram

Rhodium costs about twice as much as gold per gram. Kitco’s gold spot price was US$4,017.40 per troy ounce at 7:52 a.m. ET on 26 October 2026, or US$129.17 per gram (Kitco gold). Its rhodium bid was US$8,625 per ounce, or US$277.30 per gram, a ratio of about 2.1 to 1. Kitco showed a gap of US$1,000 between bid and ask for rhodium, which is far wider than for gold, so the real cost of buying is higher than the bid.

The two lists above use different benchmarks (Umicore quotes in euros, and its rhodium price was €288.05 per gram), so do not mix one source’s rhodium price with another source’s gold price. Take both prices from the same page, the same hour and the same currency. That is the single most common error in “rhodium vs gold” comparisons.

Platinum and palladium sit well below gold. Kitco showed platinum at US$1,541 per ounce (7:54 a.m. ET) and palladium at US$1,034 per ounce (7:54 a.m. ET) on the same morning (Kitco platinum, Kitco palladium), which is about US$50 and US$33 per gram. If you want more on gold’s own chemistry and rarity, see our guide to gold as an element.

▶ A clay explainer that follows a gold nugget from rock to ring: how gold is mined and refined. · 5:27

Rhodium price history: from the peak to today

Rhodium has been the most volatile of the group in the USGS annual averages. USGS annual average prices show rhodium falling from US$20,254 per troy ounce in 2021 to US$4,660 in 2024, a drop of 77%, then recovering to an estimated US$5,800 in 2025 (USGS, 2026). Kitco’s bid of US$8,625 on 26 October 2026 is about 49% above that 2025 estimate. Iridium moved far less over the same years, from US$5,158 to an estimated US$4,400, which is why the two metals have swapped places at the top.

Chart

Rhodium and iridium annual average prices

US$ per troy ounce

The dumbbell chart compares the USGS 2025 estimated average with Kitco’s price on 26 October 2026 for four metals. Gold, platinum and rhodium are higher; palladium is slightly lower. A one-day Kitco quote and a full-year average are different measures, so read the chart as direction, not as a return.

Rhodium or diamond: which is more expensive?

Diamond is a mineral, not a metal, and its price depends on carat weight, colour, clarity and cut, so there is no single “price per gram”. Weight for weight, the best gem diamonds cost far more than rhodium. The Pink Star, a 59.60-carat (11.92 g) Fancy Vivid Pink diamond, sold for US$71.2 million at Sotheby’s in Hong Kong in April 2017 (CNN; weight from Wikipedia). That is about US$6 million per gram, more than 20,000 times Kitco’s rhodium price per gram.

Chart

Average price last year against one quote this week

US$ per troy ounce

That record is a one-off. Ordinary gem stones sell for a tiny fraction of that, while industrial diamond is a bulk commodity sold by the carat in very low-value grades. For a gem, ask a dealer for a grading-based quote; do not mix it with the metal table above.

Where these metals are mined

Almost all rhodium and iridium comes from platinum-bearing ore, so the country table for platinum is the best guide to supply. USGS estimates South Africa mined 120 tonnes of platinum in 2025 out of about 170 tonnes worldwide, or roughly 71%, ahead of Russia at 20 tonnes and Zimbabwe at 18 tonnes. The same USGS table gives South Africa PGM reserves of 63,000 tonnes and says the largest resources and reserves are in the Bushveld Complex.

Chart

Platinum mine output by country, 2025

Tonnes, USGS estimates

For palladium the picture is more split: Russia 84 tonnes and South Africa 70 tonnes of 190 tonnes in 2025. A strike, a power cut or an export rule in either country therefore moves the whole group. The United States produced only 1.8 tonnes of platinum and 6.2 tonnes of palladium in 2025 as one Montana operation stayed on care and maintenance.

Calculator: what will your order cost?

Enter a quote copied from a price page, the weight you want and a dealer premium. The calculator also shows how much gold weighs the same in money terms. All prices are inputs: they are examples, so use today’s price.

Ruthenium, osmium and the rest of the platinum group

Ruthenium trades far below rhodium and iridium. USGS lists its annual average at US$576 per ounce in 2021 and an estimated US$690 in 2025, against US$20,254 and US$5,800 for rhodium, and Umicore’s €61.35 per gram on 26 October 2026 puts it below gold. Osmium, the densest natural metal, is rarely traded as a metal, which is why no daily board lists it. The RSC notes that iridium and osmium form an alloy used for pen tips and compass bearings.

The practical point for a mine owner is that a metal with a daily board (platinum, palladium, rhodium, iridium, ruthenium) can be valued from a screen, while a metal without one, such as osmium, needs a private quote from a refiner.

Per ounce, per gram and per kilogram: one rhodium price in three units

Kitco’s rhodium quote of US$8,625 per troy ounce on 26 October 2026 is also US$277.30 per gram and US$277,300 per kilogram. Gold at US$4,017.40 per ounce is US$129.17 per gram and about US$129,000 per kilogram. A kilogram of rhodium, at that bid, therefore costs about as much as 2.1 kilograms of gold. Buyers who move between wholesale (kilograms) and retail (ounces) quotes should convert with the single factor 31.1035 rather than by rounding.

How to read a metal price quote

• Check the unit. Troy ounce (31.1035 g), gram and kilogram are all used. Umicore quotes euros per gram, Kitco quotes US dollars per ounce.
• Check bid and ask. The bid is what a dealer pays; the ask is what you pay. For rhodium, Kitco showed US$8,625 bid and US$9,625 ask.
• Check the currency and the time. A euro quote from one day and a dollar quote from the next cannot be compared without the exchange rate for each day.
• Check the form. A spot quote is a benchmark. Dealer premiums, refining charges and taxes come on top, and the calculator below lets you add a premium.

Prices on this page will age within days. The method does not: put both metals in the same unit, from the same source, on the same day.

What mining consultants should check before valuing a PGM project

Rhodium and iridium rarely decide a project on their own. A PGM deposit is usually reported as a basket of metals (platinum, palladium, rhodium and gold, often called 4E) and valued with a basket price. Grade is quoted in grams per tonne (g/t). If a report adds rhodium revenue, ask three questions:

• What rhodium and iridium prices does it assume, from which source and date, given that the USGS annual average moved from US$20,254 to US$4,660 in three years?
• Are payable terms applied? A smelter or refiner pays only a share of the contained metal.
• How big is the rhodium share of the basket? Ask for the assay split (g/t of each metal) before accepting a headline rhodium price as a driver of value.

Our guides on the rarest metals and the rarest minerals cover scarcity as opposed to price.

Finding PGM host rocks before you drill

The largest PGM resources sit in the Bushveld Complex layered intrusion (USGS), and RSC notes that rhodium is also recovered from nickel and copper refining. Satellite imagery cannot see rhodium or iridium; it can map the rock types, structures and alteration around them, which helps a consultant choose where to send a field team. Farmonaut’s satellite-based mineral detection turns an area of interest (coordinates, KML/KMZ or a polygon) into a report of ranked target zones in 5 to 20 business days. The hero image above is a Sentinel-2 view of the Bushveld platinum belt near Rustenburg. You can request a quote, read how satellite-based mineral detection works, or contact the team. Satellite results are exploration targets, not a resource estimate.

▶ A short explainer on mineral exploration from space and why drilling in the wrong place costs as much as the right place. · 4:26

Where to check prices yourself

Frequently asked questions

What is the most expensive metal in the world?

Iridium was the most expensive publicly priced metal per gram on Umicore’s list on 26 October 2026 at €309.25, ahead of rhodium at €288.05. On USGS annual averages rhodium was ahead of iridium in 2021 to 2023 and in the 2025 estimate, and the order can change again.

Is rhodium more expensive than gold?

Yes, by about 2.1 times per gram on Kitco’s quotes of 26 October 2026 (US$277.30 against US$129.17 per gram). In 2021 the USGS average rhodium price was about 11 times that year’s gold average.

Why is rhodium so expensive?

Supply is about 30 tonnes a year, taken as a by-product of nickel and copper refining, and most of it is used in catalytic converters with little substitution (RSC). A thin dealer market also lets prices jump.

How much is iridium worth per ounce?

Umicore’s €309.25 per gram equals about €9,619 per troy ounce on 26 October 2026. USGS estimated the 2025 average at US$4,400 per ounce (its dollar figure; Umicore quotes in euros, so the two cannot be compared directly).

Which metal is the costliest per gram: gold, platinum or palladium?

Of the three, gold: €127.79 per gram against €47.35 for platinum and €33.00 for palladium (Umicore, 26 October 2026).

Is a diamond more expensive than rhodium?

Per gram, yes for gem-quality stones: the 11.92 g Pink Star sold for US$71.2 million in 2017. Industrial diamond is a low-value bulk product.

Which is the most expensive ore in the world?

No ore has a single price, because value depends on grade and the metals inside. PGM ores are often among the highest-value per tonne because of platinum, palladium and rhodium, but the figure depends on the grade and the metal basket.

Where is rhodium mined?

Mostly in South Africa’s Bushveld Complex and in Russia, as a by-product of platinum and nickel mining (RSC; USGS).

Why do the same metals have different prices on different sites?

Because of units, currencies, timing, bid versus ask and form (bars, sponge, powder). Compare quotes only from one source and one time.

Can satellites find rhodium?

No. Satellites map surface rock, structure and alteration. They help rank where to explore for platinum and nickel systems, which carry rhodium as a by-product.