Skip to content
Earth & SkyGreekEnglish

Epidote

/ˈɛpɪdoʊt/noun

A pistachio-green calcium aluminium iron silicate found in metamorphosed rock.

The Greek roots

ἐπίδοσις
epídosis
increase, addition

Literally: an addition

The story of the word

Haüy named it in 1801 because the base of the crystal's prism has one side longer than the other, an increase over what symmetry would predict. That is the sort of detail that decided mineral names before chemistry could settle them. Δόσις, a giving, is also the dose on a prescription and the second half of antidote, so epidote is a distant relation of overdose.

How it travelled
Ancient Greek → French → English
First recorded
early 19th century

Same family

doseantidoteanecdoteoverdose

In a sentence

Epidote streaked the greenstone in bright yellow-green veins.

Where you find epidote, the rock has been cooked and wetted.

More from Earth & Sky