Seraphnite in small ground slices

The mineral clinochlorine (also called penninite / seraphinite) is a phyllosilicate with the chemical formula (Mg,Fe2+)5Al(Si3Al)O10(OH)8. It is considered the magnesium-containing end member of the chlorite group, part of the micas. The dark to olive green, blue-green or white clinochlor has a glassy to pearly luster and a white streak colour. The cleavage is perfect according to crystal plane [001] and the crystal system is monoclinic. The average density is 2.65 and the hardness is 2 to 2.5. Clinochlor is not radioactive. Clinochlor is named after the Greek words clinos, "slanting" and chloros, "green". The synonym penninite is named after the Apennines in Italy. Like other chlorite minerals, clinochlor also occurs mainly in slightly metamorphic rocks. It is a typical mineral in metamorphosed mafic rocks.