Structure
Not a diagram of dots on rings — a Monte-Carlo sample of the actual probability density |ψ|² for each occupied subshell. Drag to rotate. Blue and violet mark opposite signs of the wavefunction, which is what makes bonding possible.
Measured values
Every bar shows where platinum sits among all 118 elements for that property.
Sources: IUPAC 2021 standard atomic weights · CRC Handbook of Chemistry and Physics · NIST. Values marked ~ are predicted rather than measured.
Size, to scale
Radius 139 pm — that is 0.139 nm, so about 3597 million of them side by side would span a millimetre.
Thermal range
Platinum is liquid over a 2057 K window, from 2041 K to 4098 K.
The story
The catalyst metal: platinum makes reactions happen that would otherwise need impossible conditions.
The first Europeans to encounter platinum were Spanish conquistadors in the rivers of Colombia and Ecuador during the 1520s. They called it "platina del Pinto" (little silver of the Pinto River) - a dismissive name that reflected their frustration with this "impure silver" that wouldn't melt or work like the precious metals they knew.
Indigenous peoples of South America had been working with platinum for over 1,000 years before European contact. Pre-Columbian artisans of the La Tolita culture created exquisite platinum-gold alloy jewelry and artifacts, demonstrating sophisticated metallurgical knowledge that Europeans would not achieve for centuries.
Spanish miners considered platinum a nuisance metal that contaminated gold deposits. They often threw it back into rivers, believing it was immature gold that would eventually "ripen" into the real thing. Some Spanish colonies even banned platinum mining, fearing it would be used to counterfeit gold coins.
The scientific study of platinum began when Spanish naval officer Antonio de Ulloa brought samples to Europe in 1735. His detailed observations of this mysterious metal intrigued European scientists, who recognized it as a distinct element rather than impure silver.
British metallurgist William Brownrigg conducted the first systematic study of platinum in 1750, documenting its unique properties including its high melting point and resistance to acids. His work established platinum as a legitimate subject of scientific inquiry.
French physicist Pierre-François Chabaneau achieved the first successful melting and working of platinum in 1786, developing techniques that allowed craftsmen to create the first platinum jewelry and scientific instruments in Europe.
King Louis XVI of France became fascinated with platinum and commissioned elaborate platinum objects, declaring it "the only metal fit for a king." His patronage elevated platinum from curiosity to luxury commodity, establishing its association with royalty and exclusivity.
The development of powder metallurgy techniques by French chemists allowed for the creation of larger platinum objects. They learned to reduce platinum salts to fine powder, then compress and heat the powder to form workable metal - techniques still used today.
During the French Revolution, platinum's rarity and association with royalty made it politically dangerous. Many platinum objects were hidden or destroyed, making surviving pieces from this era extremely valuable to collectors today.
English chemist William Hyde Wollaston revolutionized platinum chemistry by developing methods to purify and work with the metal on an industrial scale. His techniques for dissolving platinum in aqua regia and recovering pure metal established the foundation of modern platinum refining.
Wollaston also discovered palladium and rhodium while working with platinum residues, demonstrating the interconnected nature of the platinum group metals. His work earned him substantial wealth and established London as a center of platinum expertise.
The development of platinum crucibles and laboratory equipment revolutionized chemistry and glass manufacturing. These unreactive vessels allowed chemists to work with substances that would contaminate or destroy other containers.
The invention of the oxy-hydrogen blowpipe finally allowed platinum to be melted easily, enabling mass production of platinum objects. This technological breakthrough made platinum jewelry and industrial applications economically viable.
Russian platinum production in the Ural Mountains began supplying European markets, making platinum more widely available. Russian deposits were so rich that platinum temporarily became less expensive than gold, leading to the creation of platinum coinage.
The development of platinum-catalyzed sulfuric acid production marked the beginning of platinum's crucial role in chemical industry. This application demonstrated platinum's unique catalytic properties that would become central to modern industrial chemistry.
The 20th century brought scientific understanding of platinum's catalytic properties at the molecular level. Research revealed why platinum is so effective at facilitating chemical reactions without being consumed in the process.
The discovery of cisplatin's anti-cancer properties in 1965 by Barnett Rosenberg opened an entirely new chapter in platinum applications. This accidental discovery while studying bacterial growth has since saved millions of lives through cancer chemotherapy.
Today's platinum applications in fuel cells and automotive catalysts represent the latest chapter in this remarkable metal's ongoing story. From "worthless" river pebbles to crucial components in clean energy technology, platinum's journey reflects humanity's growing understanding of the natural world.
Applications
Platinum is the cornerstone of modern automotive emission control, making clean air possible in urban environments. Catalytic converters in gasoline engines use platinum to convert harmful carbon monoxide, nitrogen oxides, and unburned hydrocarbons into low-hazard water vapor, carbon dioxide, and nitrogen.
The automotive industry consumes over 40% of global platinum production. A typical car contains 3-7 grams of platinum in its catalytic converter, while larger vehicles may contain up to 30 grams. Diesel engines rely heavily on platinum catalysts for particulate filter systems that remove harmful soot particles.
Next-generation hydrogen fuel cell vehicles represent the future of platinum automotive applications. Fuel cells use platinum catalysts to efficiently convert hydrogen and oxygen into electricity, with water as the only emission. This technology could dramatically increase platinum demand as transportation shifts toward zero-emission solutions.
Platinum catalysts are essential in petroleum refining, particularly in reforming processes that upgrade low-octane petroleum fractions into high-octane gasoline components. These catalysts increase fuel efficiency and reduce engine knock in modern vehicles.
The chemical industry uses platinum for producing nitric acid, a crucial component in fertilizers and explosives. Platinum-rhodium gauze catalysts in the Ostwald process enable efficient conversion of ammonia to nitric acid at industrial scales.
Pharmaceutical manufacturing relies on platinum catalysts for complex organic synthesis reactions. These catalysts enable the production of life-saving medications with high purity and efficiency, particularly in creating specific molecular structures required for drug effectiveness.
Platinum's excellent electrical conductivity and corrosion resistance make it central in high-reliability electronics. Electrical contacts in critical systems use platinum to ensure consistent performance over millions of switching cycles.
Computer hard drives contain platinum in their magnetic recording layers, enabling high-density data storage. The metal's stability ensures data integrity over decades of use. Platinum is also used in solid-state drives (SSDs) for next-generation storage technology.
The telecommunications industry uses platinum in fiber optic systems and high-frequency circuits where signal integrity is paramount. Platinum's resistance to oxidation ensures long-term reliability in harsh environments.
Platinum nanoparticles are revolutionizing catalysis with their extremely high surface area and unique electronic properties. These nanoscale catalysts are more efficient than bulk platinum, reducing the amount needed for industrial processes.
In fuel cell technology, platinum nanoparticles on carbon supports provide the catalytic activity needed for efficient hydrogen-oxygen reactions. Research focuses on reducing platinum loading while maintaining performance.
Cancer treatment utilizes platinum-based chemotherapy drugs like cisplatin, carboplatin, and oxaliplatin. These compounds interfere with cancer cell DNA replication, making them effective against various tumor types.
Platinum's high melting point (1,768°C) and oxidation resistance make it essential for high-temperature applications. Glass manufacturing uses platinum-lined furnaces and equipment that can withstand extreme conditions without contaminating the product.
Aerospace applications include turbine engine components, rocket nozzles, and heat shields where platinum's combination of strength and chemical inertness is crucial for safety and performance.
Industrial furnaces and kilns use platinum heating elements and temperature sensors that maintain accuracy and durability under extreme thermal cycling conditions.
Wedding rings and engagement rings made from platinum represent a leading symbol of enduring love. Platinum's natural white luster never fades or tarnishes, symbolizing eternal commitment. Unlike white gold, platinum doesn't require rhodium plating and maintains its beautiful appearance for very long periods.
Luxury jewelry houses like Cartier, Tiffany, and Van Cleef & Arpels prize platinum for its ability to securely hold precious gemstones. The metal's density and strength make it ideal for intricate settings that showcase diamonds and colored gems to their fullest potential.
High-end watches feature platinum cases that resist scratching and corrosion. Brands like Patek Philippe and Rolex create exclusive platinum timepieces that combine exceptional craftsmanship with the prestige of wearing one of the rarest metals on Earth.
Every time you start your car, platinum catalysts spring into action, cleaning your exhaust gases before they enter the atmosphere. Your catalytic converter contains precious platinum that converts harmful pollutants into low-hazard emissions, making modern urban life possible.
Spark plugs in high-performance vehicles often feature platinum electrodes that last longer and provide more consistent ignition than conventional plugs. These plugs improve fuel efficiency and reduce maintenance needs.
Luxury and electric vehicles increasingly use fuel cells powered by platinum catalysts. These systems generate electricity from hydrogen with only water vapor as exhaust, representing the future of clean transportation.
Cancer treatment relies heavily on platinum-based chemotherapy drugs. Medications like cisplatin have saved millions of lives by targeting cancer cells while minimizing damage to healthy tissue. These drugs are particularly effective against testicular, ovarian, and lung cancers.
Pacemakers and medical implants use platinum electrodes that safely conduct electrical impulses in the human body. Platinum's biocompatibility and corrosion resistance make it ideal for long-term implantation without adverse reactions.
Dental work often incorporates platinum alloys in crowns, bridges, and orthodontic appliances. The metal's strength and resistance to oral bacteria make it a durable choice for dental restorations.
Your computer hard drive contains platinum in its magnetic storage layers, enabling the high-density data storage that makes modern computing possible. Platinum's magnetic properties and stability ensure your data remains secure for years.
High-end audio equipment uses platinum in electrical contacts and circuits to ensure the purest sound reproduction. Audiophiles value platinum's excellent conductivity and resistance to corrosion for maintaining signal quality.
Thermocouples and temperature sensors in household appliances like ovens and water heaters use platinum for accurate temperature measurement. These sensors ensure safe and efficient operation of everyday appliances.
The gasoline in your car was refined using platinum catalysts that improved its octane rating and removed impurities. These catalysts make modern fuel efficient and clean-burning.
Fertilizers that grow the food you eat are produced using platinum catalysts in nitric acid manufacturing. This process enables large-scale agriculture that feeds billions of people worldwide.
Many household cleaners and chemicals are manufactured using platinum-catalyzed processes that ensure purity and effectiveness while minimizing environmental impact.
Where it comes from
0.005 mg/kg of Earth's crust · more abundant than 37% of elements
Platinum is one of Earth's rarest elements, with an average crustal abundance of only 5 parts per billion - approximately 30 times rarer than gold. This extreme scarcity is due to platinum's high density and siderophile (iron-loving) nature, which caused most of it to sink into Earth's core during planetary formation.
The majority of accessible platinum occurs in ancient layered mafic intrusions - geological formations created when magma slowly cooled and crystallized over millions of years. These intrusions concentrated platinum group metals into economically viable deposits through complex geological processes.
Platinum deposits are typically found in association with other platinum group metals (palladium, rhodium, ruthenium, osmium, and iridium), as well as base metals like nickel and copper. This association requires sophisticated separation techniques to isolate pure platinum.
South Africa dominates global platinum production, accounting for approximately 70% of world output. The Bushveld Igneous Complex, formed over 2 billion years ago, contains the world's largest known platinum reserves. This geological wonder extends across 65,000 square kilometers and represents one of Earth's most significant mineral treasures.
Russia is the second-largest producer, with major deposits in the Norilsk-Talnakh region of Siberia. These deposits, formed by massive volcanic activity 250 million years ago, also contain significant nickel and copper resources alongside platinum group metals.
North America contributes to global platinum supply through deposits in Montana's Stillwater Complex and Canada's Sudbury Basin. These smaller but important sources help diversify global platinum supply chains.
Zimbabwe hosts the Great Dyke, a layered intrusion containing significant platinum resources that may become increasingly important as easily accessible deposits elsewhere become depleted.
Platinum mining is extraordinarily challenging and expensive. Most platinum occurs in underground deposits at depths exceeding 1,000 meters, requiring sophisticated mining techniques and substantial capital investment. A single underground mine may take 10-15 years to develop before producing its first platinum.
The refining process is equally complex. Raw platinum ore typically contains only 3-6 grams of platinum per tonne of rock, requiring the processing of massive amounts of material. The complete refining process can take 5-6 months to produce pure platinum from raw ore.
Environmental and safety considerations make platinum mining particularly demanding. Deep underground operations require extensive safety systems, while the chemical processes used in refining must be carefully managed to minimize environmental impact.
Historical platinum recovery began with alluvial deposits in Russia's Ural Mountains, where weathering and erosion concentrated platinum nuggets in riverbeds. These easily accessible surface deposits were largely exhausted by the early 20th century.
Colombia remains one of the few places where small-scale alluvial platinum mining continues. The Chocó region produces modest quantities of platinum through traditional placer mining techniques, though environmental concerns limit expansion of these operations.
River systems draining platinum-bearing geological formations occasionally yield platinum nuggets, with the largest specimens weighing several kilograms. These natural platinum specimens are prized by collectors and museums for their rarity and beauty.
Given platinum's extreme value and scarcity, recycling has become crucial for meeting global demand. Approximately 25-30% of annual platinum supply comes from recycled sources, primarily from spent automotive catalysts, electronic components, and jewelry.
Automotive catalyst recycling is particularly important, as catalytic converters contain 3-7 grams of platinum group metals. Specialized facilities recover and refine these metals, returning them to productive use.
A substantial share of supply comes from recycling. Advanced hydrometallurgical processes can recover platinum from complex alloys and contaminated materials with high efficiency.
Handling
Metallic platinum is considered very safe for handling and wearing. Its chemical inertness means it doesn't react with skin, air, or most chemicals under normal conditions. This is why platinum jewelry can be worn continuously without causing skin reactions, even in sensitive individuals.
Unlike nickel-containing alloys, platinum rarely causes allergic reactions and is often recommended for people with metal sensitivities. The metal's biocompatibility makes it suitable for medical implants and dental work.
Soluble platinum salts can cause significant health problems and require careful handling. Platinum chloride and other platinum compounds may cause severe allergic reactions, respiratory irritation, and skin sensitization.
Occupational asthma is a serious concern for workers exposed to platinum compounds in refineries and chemical plants. This condition can develop after months or years of exposure and may become permanent even after exposure stops.
Skin sensitization from platinum compounds can develop gradually. Once sensitized, individuals may experience severe allergic reactions to even trace amounts of platinum compounds. Use nitrile gloves and protective clothing when handling soluble platinum compounds.
Platinum dust and fumes pose serious respiratory risks. Industrial processes involving grinding, welding, or high-temperature processing of platinum can generate airborne particles that cause lung irritation and sensitization.
Workers in platinum refineries must use respiratory protection (minimum N95, preferably P100 filters) to prevent inhalation of platinum-containing particles. Adequate ventilation systems are essential in all platinum processing areas.
Platinum asthma affects up to 50% of workers with prolonged exposure to platinum salts. Symptoms include wheezing, chest tightness, and difficulty breathing. This condition requires immediate medical attention and permanent removal from platinum exposure.
Platinum-based chemotherapy drugs (cisplatin, carboplatin, oxaliplatin) require specialized medical supervision due to their potent effects. These medications can cause kidney damage, hearing loss, and severe nausea if not properly administered.
Healthcare workers handling platinum chemotherapy drugs must follow strict cytotoxic drug protocols including double gloving, protective gowns, and preparation in biological safety cabinets to prevent occupational exposure.
Patients receiving platinum chemotherapy require regular monitoring of kidney function, hearing, and blood counts. Hydration protocols are essential to prevent kidney damage from these powerful medications.
High-temperature processing of platinum requires specialized equipment due to its 1,768°C melting point. Extreme heat hazards necessitate proper thermal protection and emergency procedures for burns.
Chemical processing during platinum refining involves concentrated acids and toxic solvents. Workers must use appropriate chemical-resistant clothing, eye protection, and emergency shower/eyewash stations.
Due to platinum's extreme value, security measures are essential in processing facilities. Theft prevention protocols must balance security needs with worker safety requirements.
Platinum's rarity and value make disposal economically wasteful. All platinum-containing materials should be recycled through specialized precious metal recovery services rather than disposed of as waste.
Environmental contamination from platinum compounds requires professional remediation. While metallic platinum is environmentally benign, soluble platinum compounds can accumulate in ecosystems and affect wildlife.
Quick answers
Platinum (symbol Pt) is element 78 on the periodic table, a transition metal in period 6, group 10. The catalyst metal: platinum makes reactions happen that would otherwise need impossible conditions. At room temperature it is a solid.
[Xe] 4f¹⁴ 5d⁹ 6s¹, giving 6 occupied shells holding 2, 8, 18, 32, 17, 1 electrons respectively.Platinum melts at 2041.4 K (1768.3 °C) and boils at 4098 K (3824.9 °C). That puts it among the most refractory elements — it stays solid at temperatures that vaporise most metals.
The standard atomic weight of Platinum is 195.084 u. That is a weighted average across its naturally occurring isotopes, which is why it is rarely a whole number.
Platinum has a density of 21.45 g/cm³. Water is 1.0 g/cm³, so a block of platinum is about 21.5× heavier.
Platinum has a Pauling electronegativity of 2.28. The scale runs from 0.70 (francium, the least greedy for electrons) to 3.98 (fluorine, the most). Values in this middle band tend to form covalent rather than strongly ionic bonds.
Platinum was discovered in 1735 by Antonio de Ulloa. It is named after spanish platina, "little silver".
Platinum makes up about 0.005 mg/kg of the Earth's crust — genuinely rare, which is why it is expensive.