The mineral clinochloor (also called penniniet / Serafiniet) is an fylosilicaat having the chemical formula (Mg, Fe2 +) 5Al (Si3Al) O10 (OH) 8. It ranks as the magnesium-containing end member of the chlorietgroep, part of the mica. The dark brown to olive green, blue or white clinochloor a glass to pearl luster and a white stripe color. The cleavage is perfect as crystal surface  and the crystal system is monoclinic. The average density is 2.65 and the hardness is from 2 to 2.5. Clinochloor is not radioactive. Clinochloor is named after the Greek words clinos, "oblique" and chloros, "green". The synonym penniniet is named after the Apennines in Italy. Like other chlorietmineralen clinochloor also occurs mainly in light metamorphic rocks. It is a typical mineral of metamorphosed mafic rocks.