A monoclinic mineral, 4(CaMnSi₂O₆) ; pyroxene group; forms series with diopside and hedenbergite; shows clove-brown to grayish-green columnar, radiating, and spherulitic aggregates of fibers and prisms with black tarnish; in metasomatized limestones with manganese ore. Occurs at Puebla and Hildago, Mexico; Lane County, OR; Franklin, NJ; and Schio, Venetia, Italy.