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Chalcedony

/kælˈsɛdəni/noun

Quartz in microscopically fine fibres, the family that includes agate, onyx and carnelian.

The Greek roots

Χαλκηδών
Chalkēdṓn
Chalcedon, a Bithynian city

Literally: stone of Chalcedon

The story of the word

The stone is listed in Revelation among the foundations of the heavenly city, and English took it from there through Latin. Where the Greek word came from is unsettled: the obvious candidate is Chalcedon on the Bosphorus, except the city was spelled with a kappa and the stone with a chi. Others read χαλκός, copper, in the first syllable instead.

How it travelled
Ancient Greek → Latin → English
First recorded
14th century

Same family

chalcopyritechalcolithic

In a sentence

The seal was cut from a blue-grey chalcedony no bigger than a thumbnail.

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