The Most Expensive Elements (and Why They Cost So Much)

Gold is the element everyone thinks of as valuable, but it’s nowhere near the top of the price list. The most expensive elements fall into two very different categories: metals that are rare but mined and traded in bulk, and synthetic elements made in nuclear reactors a few micrograms at a time.

A note on numbers: commodity prices change daily, and some precious metals have doubled or halved within a few years. This article compares elements by category and relative cost rather than quoting prices that would soon be out of date.

Category 1: synthetic elements — astronomically expensive

Elements that don’t exist in nature have to be made in reactors or accelerators, often at enormous cost and in tiny amounts.

• Californium (element 98) is often cited as the most expensive element ever sold. It’s produced in only a handful of high-flux reactors in the world, a few tens of milligrams per year. Californium-252 emits neutrons, and is used to start up nuclear reactors, to scan for gold and silver ores, and in some cancer treatments. Prices have been quoted in the tens of millions of dollars per gram.
• Plutonium, americium and other actinides are also made in reactors. Americium-241 is used in smoke detectors — each detector contains only a fraction of a microgram.
• Superheavy elements like oganesson can’t be bought at all. Only a few atoms have ever existed, each for a fraction of a second.

Category 2: precious metals traded in bulk

These are mined, refined and traded as commodities.

• Rhodium — usually the most expensive of the traded precious metals, often several times the price of gold. It’s one of the rarest elements in the crust, it’s produced mainly as a by-product of platinum and nickel mining (largely in South Africa and Russia), and about 80% of it goes into the catalytic converters that clean car exhaust.
• Iridium — extremely rare, dense and corrosion-resistant; used in spark plug tips, crucibles for growing crystals, and electrodes.
• Palladium — also a catalytic converter metal, especially in petrol cars, and in electronics and hydrogen purification.
• Gold — valued for jewellery, investment and electronics. Its price is driven as much by its role as a store of value as by industrial demand.
• Platinum — catalytic converters, jewellery, laboratory equipment and the anti-cancer drug cisplatin.
• Ruthenium and osmium — platinum-group metals with smaller markets.

Most of these belong to the platinum group metals — six chemically similar elements that occur together in the same ores. See the platinum group metals.

Category 3: expensive because they’re hard to purify

Some elements aren’t especially rare, but separating them in pure form is difficult:

• Scandium is fairly abundant in the crust, but rarely concentrated in ores. It’s added in small amounts to aluminium alloys for aerospace and high-end sports equipment.
• Some rare earth elements, such as lutetium, are costly to separate from their chemically near-identical neighbours. See rare earth elements.
• Isotopically pure materials — like highly enriched silicon-28 or helium-3 — can cost far more than the ordinary element, because separating isotopes is so hard.

What sets an element’s price?

• Abundance in the crust — and, importantly, whether it’s concentrated into mineable ore.
• Whether it’s a by-product. Rhodium’s supply depends on how much platinum and nickel are mined, not on rhodium demand. When demand for rhodium surges, supply can’t simply increase, and prices spike.
• Difficulty of extraction and refining.
• Industrial demand. Emissions rules for cars have been a major driver of rhodium and palladium prices.
• Investment and speculation, especially for gold, silver and platinum.

The cheapest elements

At the other end, elements like oxygen and nitrogen (separated from air), sulfur (a by-product of oil refining), iron, silicon, sodium and chlorine cost very little in bulk. Chlorine and sodium hydroxide are made by electrolysing salt water on a huge scale.

Quick answers

What is the most expensive element? Among elements that are actually sold, californium. Among traded metals, usually rhodium.

Is gold the most expensive metal? No. Rhodium, and at times iridium and palladium, have traded higher.

Why is diamond not on this list? Diamond is a form of carbon, one of the cheapest elements. Its price reflects the crystal, not the element.