chlo·rite 1 
(klôr
īt
′)
n. A generally green or black secondary mineral, (Mg,Fe,Al)6(Si,Al)4O10(OH)8, often formed by metamorphic alteration of primary dark rock minerals, that appears as a spot of green and resembles mica.
[Latin chlōrītis, a green precious stone, from Greek khlōrītis, from khlōros, green; see ghel-2 in the Appendix of Indo-European roots.]
chlo·ritic (klôr-ĭtĭk) adj.