Melting and boiling point of pure gold
Pure gold has a melting point of 1,064.18°C (1,947.5°F / 1,337.3 K) and a boiling point of roughly 2,856°C (5,173°F). The energy needed to turn solid gold at its melting point into liquid — the latent heat of fusion — is about 12.55 kJ/mol. Gold is a relatively low-melting precious metal: silver melts at 962°C and copper at 1,085°C, but platinum needs 1,768°C, which is why platinum work requires specialist equipment that ordinary gold work does not.
Melting point by carat
Alloy metals lower the melting point and spread it across a range — the alloy starts to soften at the "solidus" temperature and is fully liquid at the "liquidus". Exact figures depend on the specific recipe, but typical values are:
It is not a straight line: a 9ct alloy can melt higher than 14ct because low-gold alloys are dominated by the copper–silver mix rather than the gold. White gold sits higher than yellow gold of the same carat because nickel or palladium raise the melting point, and gold solder is formulated to melt lower still — in "easy", "medium" and "hard" grades — so a jeweller can join a piece without melting the piece itself.
How gold is melted in practice
A handheld butane or propane torch reaches 1,200–1,300°C at the tip — enough to melt small amounts of gold in a ceramic or graphite crucible, though heat loss makes it slow and marginal for pure gold. Jewellers and refiners use oxy-propane or oxy-acetylene torches, electric muffle furnaces or induction melters for anything larger. A pinch of borax is added as a flux: it dissolves surface oxides from the alloy metals and helps the molten gold form a clean bead. Molten gold glows bright orange-yellow and pulls itself into a sphere under surface tension.
Using melting point to spot fake gold
Melting behaviour is a strong tell. Brass — a common base for fake "gold" bars and jewellery — melts at around 900–940°C, so a supposedly pure gold item that softens well below 1,064°C is suspect. Tungsten, used to fill counterfeit bars because its density nearly matches gold, melts at 3,422°C and will not melt under any jeweller's torch. Melting is destructive, though, so it is a refiner's test rather than a first check — start with the hallmark and weight on the scrap gold page and the gold density test.
Does melting gold change its purity?
Melting pure gold does not reduce its purity — gold does not oxidise or burn, and its boiling point is far above any melting temperature, so losses are negligible. Melting alloyed gold is different: the base metals (copper, zinc) can oxidise and burn off, so a melted-down 9ct or 14ct piece loses a little total weight, but the pure gold content itself is essentially unchanged. Refiners assay the gold after melting to certify the new purity.