Part of the Faculty of Social Sciences at the University of Victoria, PACTAC is a pioneering, multidisciplinary research centre, and home to the electronic scholarly journal CTheory, CTheory Archive, and CTheory Multimedia.
Rocks: Rocks are a composed of one or more minerals. A rock can be made up of only one mineral or, as shown in the figure, a rock can be made up of a number of different minerals. So, rocks are composed of one or more minerals and minerals are composed of one or more elements. Previous Item: Why should we study rocks? Go Up: Learn About Rocks
Igneous rocks are rocks formed from the crystallization of a liquid (molten rock). Igneous rocks may be divided into two categories. Intrusive or plutonic rocks crystallize from magma beneath the earth's surface.gneous Rocks. Of the three principal rock types (igneous, sedimentary, and metamorphic), igneous rocks can be thought of as primary rocks because they crystallize from a liquid. Sedimentary and metamorphic rocks, which we will study later, may be thought of as derivative rocks.