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Material World
Element · Ga

Gallium

A metal that melts in the hand, and the basis of every blue and white LED.

Semiconductor

Gallium melts at just under thirty degrees Celsius, so a lump held in a warm palm becomes liquid. That is a curiosity; its importance is semiconducting. Gallium nitride and gallium arsenide have direct band gaps, which silicon does not, and can therefore emit light efficiently.

Every white LED in general lighting is a blue gallium nitride emitter behind a phosphor. The shift from incandescent to LED lighting — a substantial fraction of global electricity demand — rests on this element.

Extraction

Never mined for its own sake. Gallium is recovered in small quantities from the liquors of bauxite refining and zinc processing, which ties its supply to the production levels of aluminium and zinc rather than to demand for gallium.

Uses

Gallium's importance is semiconductor compounds rather than the metal. Gallium nitride produces blue and white LEDs, which transformed lighting, and its ability to switch high voltages efficiently is displacing silicon in fast chargers and power electronics.

Gallium arsenide is used in high-frequency amplifiers — mobile phone and satellite transmitters — and in the most efficient solar cells, which fly on spacecraft. The pure metal is a curiosity that melts in the hand, but almost none is used that way.

Medium confidence Weak evidence

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 used as

  • Lighting — application · gallium nitride is the emitter in every white LED
  • Photovoltaics — application · gallium arsenide gives the most efficient cells, at a cost that restricts them to space and concentrators

is sourced from

  • Bauxite — rock · as a by-product of the Bayer process
  • Aluminium — element · recovered from Bayer process liquor, which is aluminium refining — the same by-product pattern as silver from lead, and the reason gallium production is capped by somebody else's output

is produced by

is found in

  • Gallium arsenide — compound · recovered from Bayer process liquor, which is the only place gallium comes from in quantity Wikidata
  • Gallium nitride — compound · and there is no gallium mine anywhere — it is recovered from Bayer process liquor as a by-product of making aluminium

is a source for

  • Gallium nitride — compound · produced overwhelmingly in China, which introduced export controls in 2023 — a vulnerability that comes from the metal being somebody else's by-product rather than from any scarcity

Sources

  • Material World
    Our own writing
  • Wikidata
    Wikimedia Foundation · Creative Commons CC0 1.0 Universal (public domain dedication)
  • PubChem
    US National Library of Medicine · Mixed — aggregated third-party content, rights retained by depositors
  • NIST — National Institute of Standards and Technology
    United States Department of Commerce · US Government work — public information, credit requested

Questions this page answers

Where it comes from, and what it becomes

Follow Gallium back to what it starts as, and forward into what it becomes. Each step is a documented one — a real route material takes, not a chain of inference.

Upstream — what it comes from

  • Gallium → is sourced from (recovered from Bayer process liquor, which is aluminium refining — the same by-product pattern as silver from lead, and the reason gallium production is capped by somebody else's output) → Aluminium → is extracted from (via alumina — bauxite is refined by the Bayer process before smelting) → Bauxite → is sourced from (the residue of prolonged tropical weathering, which strips the silica and alkalis out of an aluminosilicate rock and leaves the aluminium behind — basalt is one common parent among several) → Basalt → is sourced from (partial melting of mantle peridotite is what basalt magma is — the residue left behind stays peridotite, depleted of what went into the melt) → Peridotite → is composed of (the mineral that defines the rock and gives it its name — a peridotite is olivine-dominant by definition) → Olivine
  • Gallium → is sourced from (as a by-product of the Bayer process) → Bauxite → is sourced from (the residue of prolonged tropical weathering, which strips the silica and alkalis out of an aluminosilicate rock and leaves the aluminium behind — basalt is one common parent among several) → Basalt → is sourced from (partial melting of mantle peridotite is what basalt magma is — the residue left behind stays peridotite, depleted of what went into the melt) → Peridotite → is composed of (the mineral that defines the rock and gives it its name — a peridotite is olivine-dominant by definition) → Olivine
  • Gallium → is produced by (recovered from the Bayer process liquor, which carries the gallium that came in with the bauxite) → Solvent extraction and electrowinning → takes as input (in the low-grade and oxidised ores that flotation cannot economically treat, with bacteria oxidising the sulfide into a form the acid can attack) → Chalcopyrite
  • Gallium → is sourced from (recovered from Bayer process liquor, which is aluminium refining — the same by-product pattern as silver from lead, and the reason gallium production is capped by somebody else's output) → Aluminium → is produced by (collects at the cathode while the carbon anodes are consumed) → Hall–Héroult process → takes as input (dissolved in molten cryolite and electrolysed) → Aluminium oxide → is sourced from (dissolved out with hot caustic soda in the Bayer process) → Bauxite → is sourced from (the residue of prolonged tropical weathering, which strips the silica and alkalis out of an aluminosilicate rock and leaves the aluminium behind — basalt is one common parent among several) → Basalt
  • Gallium → is produced by (recovered from the Bayer process liquor, which carries the gallium that came in with the bauxite) → Solvent extraction and electrowinning → takes as input (a carbonate dissolves straight into acid, which is why an oxidised orebody goes to a leach pad and the sulfide beneath it goes to a smelter) → Malachite
  • Gallium → is produced by (recovered from the Bayer process liquor, which carries the gallium that came in with the bauxite) → Solvent extraction and electrowinning → takes as input (leached with acid or alkali depending on the host rock, which is what decides the flowsheet of a uranium mill) → Uraninite

These are the most distinct paths back. Gallium can be traced through others besides.

Downstream — what it becomes

  • Gallium → is a source for (produced overwhelmingly in China, which introduced export controls in 2023 — a vulnerability that comes from the metal being somebody else's by-product rather than from any scarcity) → Gallium nitride → is used to make (as the high-electron-mobility transistor that has taken most of the high-power radio-frequency market — 5G base stations, radar and satellite transmitters) → Transistor → is used in (the component every other modern technology is assembled from, and one nobody ever sees) → Electronics manufacture → is associated with (and the supply chain it produced is the deepest and most concentrated in the world economy) → The semiconductor era complete chain
  • Gallium → is used as (gallium nitride is the emitter in every white LED) → Lighting
  • Gallium → is used as (gallium arsenide gives the most efficient cells, at a cost that restricts them to space and concentrators) → Photovoltaics
  • Gallium → is a source for (produced overwhelmingly in China, which introduced export controls in 2023 — a vulnerability that comes from the metal being somebody else's by-product rather than from any scarcity) → Gallium nitride → is associated with (and it is the part of it that arrived late — red and green LEDs existed from the 1960s, and lighting waited thirty years for blue) → The semiconductor era complete chain
  • Gallium → is a source for (produced overwhelmingly in China, which introduced export controls in 2023 — a vulnerability that comes from the metal being somebody else's by-product rather than from any scarcity) → Gallium nitride → is used as (a blue GaN emitter behind a yellow phosphor is what every white LED actually is, and the displacement of incandescent lighting by LED is among the largest energy efficiency changes of the century) → Lighting
  • Gallium → is a source for (produced overwhelmingly in China, which introduced export controls in 2023 — a vulnerability that comes from the metal being somebody else's by-product rather than from any scarcity) → Gallium nitride → is used as (in the power amplifiers of 5G base stations, where it delivers far more power per millimetre of device width than gallium arsenide) → Telecommunications

These are the most distinct paths onward. Gallium ends up in others besides.