'agate' originates from Greek, specifically the word 'achates,' where 'achates' referred to a river in Sicily where the stone was found.

'achates' transformed into the Latin word 'achates,' and eventually became the modern English word 'agate' through Old French 'agate.'

Initially, it referred to the stone found in the Achates river, but over time it evolved into its current meaning of a type of quartz used as a gemstone.