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 gabbro Gabbro. Credit: Mineral Information Institute A dense, dark, course-grained igneous rock consisting largely of plagioclase feldspar, pyroxene, and olivine. Gabbro is the intrusive (i.e., cooled and solidified underground) equivalent of basalt. Accessory minerals in gabbros include apatite, hornblende, ilmenite, and magnetite. A gabbro containing nickel at Sudbury in Canada is one of the richest sources known of that metal. 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