The 10 rarest metals are extremely scarce in the Earth’s crust and often very valuable.
They include rhodium, platinum, gold, iridium, osmium, palladium, rhenium, tantalum, indium, and ruthenium.

What are the 10 rarest metals?

These metals are prized for their corrosion resistance, high melting points, and catalytic or electronic properties.
They are widely used in electronics, aerospace, jewelry, and advanced industrial applications.

Here’s a detailed guide to the 10 rarest metals in the world, including their properties, applications, and why they are so rare. These are mostly non-ferrous and precious metals, many of which are part of the platinum group metals (PGMs).

1. Rhodium (Rh)

Atomic number: 45
Density: 12.41 g/cm³
Melting point: 1964 °C
Properties: Silvery-white, extremely corrosion-resistant, high reflectivity
Occurrence: Found in platinum and nickel ores; extremely rare
Applications: Catalytic converters (automobiles), jewelry plating, chemical catalysts
Why Rare: Mining production is very low (~30 tons/year worldwide)

2. Ruthenium (Ru)

Atomic number: 44
Density: 12.37 g/cm³
Melting point: 2334 °C
Properties: Hard, brittle, corrosion-resistant, part of platinum group
Occurrence: Found in platinum ores
Applications: Electrical contacts, thick-film resistors, chemical catalysts
Why Rare: Low crustal abundance (~0.001 ppm) and limited mining

3. Osmium (Os)

Atomic number: 76
Density: 22.59 g/cm³ (heaviest metal)
Melting point: 3045 °C
Properties: Hard, brittle, bluish-silver, extremely dense
Occurrence: Found in platinum ores
Applications: Fountain pen tips, electrical contacts, alloys for hardness
Why Rare: Rarely occurs in pure form; extremely dense and hard to process

4. Iridium (Ir)

Atomic number: 77
Density: 22.56 g/cm³
Melting point: 2466 °C
Properties: Corrosion-resistant, very hard, brittle, high melting point
Occurrence: Platinum ores in South Africa and Russia
Applications: Spark plugs, crucibles, aerospace alloys, electrodes
Why Rare: Extremely resistant to corrosion; very low crustal abundance

5. Platinum (Pt)

Atomic number: 78
Density: 21.45 g/cm³
Melting point: 1768 °C
Properties: Ductile, corrosion-resistant, excellent catalyst
Occurrence: South Africa, Russia, Canada
Applications: Catalytic converters, jewelry, chemical industry, electrodes
Why Rare: Found only in small quantities in ores; high demand increases rarity

6. Gold (Au)

Atomic number: 79
Density: 19.32 g/cm³
Melting point: 1064 °C
Properties: Highly malleable, corrosion-resistant, excellent electrical conductor
Occurrence: Alluvial deposits, veins of quartz, placer deposits
Applications: Jewelry, electronics, investment, dentistry, aerospace
Why Rare: Limited natural deposits and high global demand

7. Rhenium (Re)

Atomic number: 75
Density: 21.02 g/cm³
Melting point: 3186 °C
Properties: High melting point, corrosion-resistant, dense, refractory
Occurrence: Found in molybdenum and copper ores
Applications: Superalloys for jet engines, thermocouples, catalysts
Why Rare: Extremely low natural abundance (~1 ppb in crust)

8. Palladium (Pd)

Atomic number: 46
Density: 12.02 g/cm³
Melting point: 1554 °C
Properties: Soft, ductile, corrosion-resistant, excellent catalyst
Occurrence: Found in platinum ores, Russia, South Africa, Canada
Applications: Catalytic converters, jewelry, electronics, hydrogen storage
Why Rare: Limited production, high industrial demand

9. Indium (In)

Atomic number: 49
Density: 7.31 g/cm³
Melting point: 156.6 °C
Properties: Soft, malleable, low melting point, excellent conductor
Occurrence: Found as a by-product of zinc and lead ores
Applications: Touch screens, LCDs, semiconductors, alloys
Why Rare: Extremely limited primary sources; mined as by-product

10. Tantalum (Ta)

Atomic number: 73
Density: 16.69 g/cm³
Melting point: 3017 °C
Properties: Corrosion-resistant, very high melting point, ductile
Occurrence: Found in tantalum-niobium ores, mainly in Africa and Australia
Applications: Electronics (capacitors), aerospace alloys, surgical instruments
Why Rare: Limited supply, expensive to extract and refine

11. Summary Table

Metal	Symbol	Density (g/cm³)	Melting Point (°C)	Key Uses	Rarity Reason
Rhodium	Rh	12.41	1964	Catalytic converters, jewelry	Extremely rare, low mining output
Ruthenium	Ru	12.37	2334	Electrical contacts, catalysts	Low abundance in crust
Osmium	Os	22.59	3045	Hard alloys, fountain pens	Extremely dense, rare
Iridium	Ir	22.56	2466	Electrodes, aerospace	Very corrosion-resistant, scarce
Platinum	Pt	21.45	1768	Catalysts, jewelry	Small quantities in ores
Gold	Au	19.32	1064	Jewelry, electronics	Limited deposits, high demand
Rhenium	Re	21.02	3186	Jet engines, superalloys	Very low natural abundance
Palladium	Pd	12.02	1554	Catalytic converters, electronics	Limited supply, high industrial demand
Indium	In	7.31	156.6	LCDs, touchscreens	By-product of zinc, scarce
Tantalum	Ta	16.69	3017	Electronics, aerospace	Limited deposits, expensive extraction

Conclusion:

Most rare metals are non-ferrous and belong to platinum group metals.
Rhodium is the rarest and most expensive, while metals like gold and platinum are highly valued.
They are rare due to low crustal abundance, difficult extraction, and high industrial demand.