altun primarily denotes “gold” and can be used attributively for “golden, made of gold”. It is attested from the earliest inscriptions in altun kümüş “gold and silver” and in Tunyukuk 48 in sarığ altun ürüŋ kümüş “yellow gold and white silver”. Old Uyghur texts additionally attest gold bars, gold leaf, gold coins and altun öŋlüg “gold-coloured”. The expression sarığ altun shows that altun is fundamentally a metal name rather than a basic colour adjective.
The deeper origin of altun is uncertain. Mongolic altan “gold” is generally regarded as an early borrowing from Turkic. Räsänen proposed a formation from *āl “red” and a metal name *ton “copper”, but this analysis is disputed and the proposed segmentation is not established Turkic morphology. Sakha altan now means “copper” and its route of transmission is disputed.