Schists (from the Greek skhistos: capable of splitting) are metamorphic rocks, transformed by the high temperatures and pressures they experienced during the formation of the Hercynian mountain range. Originally, they were more or less clayey sediments deposited on the shores of an ocean located between two continents, which transformed into schists through the recrystallization of minerals. Here we find a sericite schist, containing small mica crystals that give it a slightly lustrous appearance.