English
leucocratic
From leuco- + -cratic.
Proto-Indo-European *lewk- ‘white’
Proto-Hellenic *leukós ‘white’
Ancient Greek λευκός ‘white’
English leuco
Today it means
adj Light in color, containing at least 90% felsic minerals.
Language periods are conventional ranges, not dates for this word.
Etymograph / leucocratic