'epidote-rich' originates from English, formed by combining the mineral name 'epidote' (from French 'épidote', ultimately from Greek 'epidōtos' meaning 'given' or 'added') and the adjective element '-rich' (from Old English 'rice'/'ric' meaning 'powerful, abundant').

'epidote' entered scientific English in the late 18th century from French 'épidote', itself from Greek 'epidōtos'; the element '-rich' derives from Old English 'rice'/'ric', passed through Middle English to become modern English 'rich', and is used productively to form compounds meaning "abundant in".

The mineral name 'epidote' originally referenced the mineral (name based on Greek for 'given/added'); the modern compound 'epidote-rich' straightforwardly means 'rich in epidote' and retains that literal, descriptive sense.