GEOLOGY & PLANETARY SCIENCE A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site pyrolusite A soft, gray-black oxide mineral composed of manganese (IV) oxide (MnO2). Of widespread occurrence, pyrolusite (pyrolucite) is the chief ore of manganese. It is a secondary mineral of aqueous origin crystallizing in the tetragonal system. See also manganite. Related category    • GEOLOGY AND PLANETARY SCIENCE Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP