Platinum
A metal too refractory for the Spanish to melt, discarded as an impurity in silver, and now central to catalysis.
Platinum's melting point of 1,768 °C put it beyond the reach of pre-industrial furnaces, and early Spanish colonists in Colombia treated it as an unwanted contaminant of alluvial gold — the name is a diminutive of plata, silver, meaning something like 'lesser silver'.
Its value now rests on catalysis. Platinum surfaces bind reactants strongly enough to weaken their bonds and weakly enough to release the products, which is a narrow window few materials occupy. Catalytic converters, petroleum reforming and fuel cells all depend on it.
Uses
Platinum's uses rest on catalysis and inertness. Catalytic converters are the largest single application, where platinum-group metals convert engine exhaust to less harmful gases. It also catalyses petroleum reforming and nitric acid production.
Its inertness makes it the standard material for laboratory crucibles and electrodes, and for implanted electrodes in pacemakers and neural stimulators, where the body must not react to it. Jewellery is a significant use, and investment demand is real but volatile.
How we know: checked recently · only one source, so there is nothing to cross-check it against · stated directly by the source.
How this connects
Where a connection has been confirmed by an outside reference, that reference is named beside it.
is a source for
- Osmium — element · from the residues of platinum refining
- Palladium — element · and of platinum mining
- Ruthenium — element · and of platinum refining
- Osmiridium — alloy · recovered from platinum-group concentrate and from the placer deposits platinum itself is panned from — not manufactured
is used as
- Catalysis — application · autocatalysts, petroleum reforming and fuel cells
- Jewellery and adornment — application · denser, harder to work and more expensive than gold, and it holds a stone more securely, which is why the setting is platinum even when the band is not
is an alternative to
- Rhodium — element · complementary rather than substitutable — they catalyse different halves of the reaction
- Palladium — element · in autocatalysts, and the clearest case of substitution tracking price: carmakers moved to palladium when platinum was expensive and back again when palladium overtook it. The two are not interchangeable across the board — diesel exhaust needs platinum
- Iridium — element · in crucibles and electrodes, where iridium's higher melting point and resistance to attack are worth its greater scarcity
- Gold — element · in jewellery, where platinum is denser, whiter, does not need plating to stay white, and is worked by a different trade at a different price
is produced by
- Electrorefining — process · collected in the slimes, where the copper's own refining concentrates it
is extracted from
- Sperrylite — mineral · the most important platinum mineral, though most platinum comes from nickel-copper sulfide refining Wikidata
is used in
- Catalytic converter — object · in diesel exhaust, where it tolerates the conditions palladium does not
is a component of
- Osmiridium — alloy · a few per cent, from the placer gravels the grains are recovered from
is produced at
- Bushveld Igneous Complex — place · from the Merensky Reef and the UG2 chromitite, in seams often under a metre thick and followed for tens of kilometres
is found at
- Bushveld Igneous Complex — place · concentrated by two billion years of magmatic layering into seams found essentially nowhere else
is found in
- Sperrylite — mineral Wikidata
Sources
- Material WorldOur own writing
- Wikimedia Foundation · Creative Commons CC0 1.0 Universal (public domain dedication)
- US National Library of Medicine · Mixed — aggregated third-party content, rights retained by depositors
- United States Department of Commerce · US Government work — public information, credit requested