h₂erǵ-
“to be white, to shine”white, bright, silver
Root for whiteness/brightness, yielding Latin argentum (silver), Greek arguros.
Discussion
The PIE root *h₂erǵ- (to be white, to shine, to gleam with silver brightness) produced the vocabulary of whiteness and silver across the major branches — connecting the visual quality of metallic lustre to the precious metal that most perfectly embodied it.
Latin argentum (silver) continues the root transparently: Argentina ("the Silver Land"), argent (the heraldic term for silver/white), and the chemical symbol Ag. French argent (money) shows the characteristic Romance development where the metal-word became the word for money — in French, argent means both silver and cash.
Greek árgyros (ἄργυρος, "silver") gave English Argonaut ("Argo-sailor" — the ship's name may relate to "shining/swift"). The related argós ("white, bright, swift") appears in the name Argos (the watchful dog, the bright-eyed one).
Sanskrit rajatá- ("silver, white") preserves the Indo-Iranian reflex. Armenian arcat' (silver) provides further attestation.
The already-treated *h₂erǵ-nt-om (the specific silver-metal formation) covers the derived nominal form in detail. The base root *h₂erǵ- encompasses not just silver but whiteness and brightness generally — the quality that made silver the most visually striking metal in the ancient world. The PIE speakers named their brightest metal after its most visible property: the gleam.
Notes
Pokorny 64. Possibly overlaps with *h2erg-.