Abstract: Infrared spectroscopy is a rapid method of distinguishing between pseudomalachite and its polymorphs reichenbachite and ludjibaite. This technique, backed by X-ray diffraction has shown that a number of specimens labelled ‘pseudomalachite’ from Cornwall, in particular from Old Gunnislake mine, are of reichenbachite, thus identified for the first time from the British Isles. Reichenbachite has also been identified with pseudomalachite from Miguel Vacas mine, Vila Viçosa, Evora, Portugal. Identification of pseudomalachite from a number of other localities world-wide has been confirmed, and some specimens have been shown to be arsenatian.