noun
chlorite
A group of greenish clay minerals; used in mineralogy and geology.
この岩石には緑泥石が多く含まれている。
This rock contains a lot of chlorite.
From 緑 (ryoku, 'green') + 泥 (dei, 'mud') + 石 (seki, 'stone'), referring to its greenish color and clay-like appearance.