Tantalum · element 73
The metal that ignores acid, hides inside every smartphone and started a debate about where our minerals come from
Key facts
Anders Gustaf Ekeberg, the Swedish chemist who found tantalum in 1802, named it after Tantalus, the figure in Greek myth condemned to stand in water he could never drink. The oxide he had isolated sat in acid without absorbing any of it, and the name was a joke about that frustrating inertness. Two centuries later the joke has become the whole point. Tantalum's refusal to react with almost anything is why it is inside your phone, inside surgical implants and inside chemical plants handling the harshest acids.
Tantalum is a hard, heavy, grey blue metal that can be drawn into fine wire and rolled into thin sheet. It is one of the refractory metals, with a melting point among the highest of any element, and it owes its chemical toughness to a thin, self healing oxide film that forms the instant the bare metal meets air.
Where it is found
Tantalum occurs in the mineral tantalite and its close relative columbite, often together in a mixture called coltan, and always in company with its lighter twin niobium. The largest producers in recent years have been the Democratic Republic of the Congo, Rwanda, Brazil and Nigeria, with additional supply from Australia, China and Ethiopia.
Much of the Congolese output comes from small scale, hand dug mines, and in the 2000s the trade in coltan was linked to funding armed groups during the civil war. That led to tantalum being named a conflict mineral in United States law in 2010, alongside tin, tungsten and gold, and to the tracing schemes that now follow it from mine to smelter.
How it was discovered
Ekeberg isolated the new oxide from minerals found in Sweden and Finland, and announced tantalum in 1802. A year earlier the English chemist Charles Hatchett had found columbium, later renamed niobium, in a mineral from America. The two were so similar that for over forty years many chemists insisted they were the same element.
The German chemist Heinrich Rose settled the matter in 1846 by showing that tantalite contained two distinct metals. He named the second one niobium after Niobe, the daughter of Tantalus, cementing the family connection in the periodic table.
What we use it for
Electronics consume the largest share. A tantalum capacitor uses a pellet of sintered tantalum powder coated with an extremely thin, uniform oxide layer as its insulator. Because the layer is so thin and the powder so porous, the capacitor stores a large charge in a very small volume and stays stable across a wide temperature range. Phones, laptops, car electronics, hearing aids and medical implants all rely on them.
The body does not reject tantalum. It is used for bone plates, skull repair plates, dental implants and the porous coatings on joint replacements that let bone grow into them. In the chemical industry tantalum linings, heat exchangers and valves handle hot acids that would destroy stainless steel.
Tantalum is added to nickel based superalloys for jet engine turbine blades, and tantalum carbide is one of the hardest cutting tool materials. Tantalum oxide gives camera lenses a high refractive index, allowing thinner, sharper glass.
Reading the numbers
Tantalum melts at about 3017 °C and boils near 5458 °C. Among metals only tungsten, rhenium and osmium melt at higher temperatures. Its density of 16.69 grams per cubic centimetre is more than twice that of iron and well above lead.
The configuration [Xe] 4f14 5d3 6s2 puts it in group 5 beneath niobium and vanadium, and like niobium its chemistry is dominated by the +5 state. The full 4f shell beneath the valence electrons shrinks the atom to almost exactly niobium's size, which explains why the two metals were confused for decades and why they still occur together in every ore. A first ionisation energy of about 761 kJ/mol and an electronegativity of 1.5 are on the higher side for an early transition metal, consistent with a strong, stable oxide. Natural tantalum is almost entirely tantalum-181, with a trace of the extraordinarily long lived isomer tantalum-180m.
Safety and the environment
Tantalum is one of the most biologically inert metals known, which is exactly why it is used inside the body. Its compounds are of low toxicity, though tantalum powder, like most fine metal powders, can ignite.
The environmental and ethical issues surround mining rather than the metal. Artisanal coltan mining has damaged habitats and, historically, funded conflict. Industry traceability programmes now audit smelters, and recycling of tantalum from capacitor scrap and superalloy turnings supplies a meaningful fraction of demand.
Did you know?
- Tantalum is named after Tantalus, who was punished with unquenchable thirst, because its oxide would not absorb acid.
- Niobium was named after Niobe, the daughter of Tantalus, because the two metals were so hard to tell apart.
- Tantalum capacitors in phones and laptops pack a large charge into a tiny space thanks to an oxide layer only nanometres thick.
- The metal is so compatible with the body that it is used for skull plates and porous coatings that bone grows into.
- Tantalum is one of four minerals legally defined as conflict minerals in the United States, together with tin, tungsten and gold.
- Natural tantalum contains a trace of tantalum-180m, a nuclear isomer with a half-life so long it has never been observed to decay.
More in the transition metals
Column-mates come first, since elements in one column have outer electrons arranged in a similar way and tend to behave alike; the rest are the nearest neighbours in the family.
See all 38 transition metals on one page, or browse all 118 elements.
Frequently asked questions
What is tantalum used for?
Its largest use is in small, high performance capacitors inside phones, computers and cars. It is also used for medical implants because the body tolerates it, in corrosion resistant chemical equipment, in jet engine superalloys and in high refractive index camera lens glass.
Why is tantalum a conflict mineral?
A significant share of tantalum ore, known as coltan, comes from small scale mines in central Africa, and during the Congolese wars the trade helped fund armed groups. United States legislation in 2010 required companies to trace their tantalum, along with tin, tungsten and gold, back to its source.
Is tantalum safe in the body?
Yes, tantalum is one of the most bioinert metals known. It does not corrode in body fluids or provoke rejection, so surgeons use it for bone plates, cranial repairs and coatings on joint implants that encourage bone to grow into them.
Why is tantalum so resistant to corrosion?
The bare metal instantly forms a thin, tightly bonded layer of tantalum oxide that acids and most other chemicals cannot penetrate. If the layer is scratched it reforms immediately, so the protection is self healing.
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Written by Anthony. Updated September 2026. Numerical data from Periodic-Table-JSON (CC BY-SA), cross-checked against the Tantalum reference article. Spotted an error? Tell us.