Mimetite, or mimethesite, is a mineral belonging to group VII (arsenates) according to the Strunz classification. It contains arsenic and has the chemical formula Pb5(AsO4)3Cl. Its name comes from the Greek word mimethes, meaning "imitator," due to its potential for confusion with pyromorphite. It was first described as a separate mineral species in 1832 by the French mineralogist François Sulpice Beudant.