The wingspan is 40–52 mm. The upper surface of the forewings is black with white markings towards the apex. The upper surface of the hindwings is black with white markings on the outer edge, and a characteristic large metallic-blue spot. This blue spot is smaller and more a dull purple in females. The underside of the forewings is brown with white markings corresponding to those on the upper surface. The under surface of the hindwings is almost uniform brown.