Classification diagram for igneous rocks. Igneous rocks are classified according to the relative abundances of different minerals. A given rock is represented by a vertical line in the diagram. In the ultramafic field, the arrows represent a rock containing 40% olivine and 60% pyroxene. The name an igneous rock gets depends not only on composition, but on whether it is intrusive or extrusive
Provide an introduction to igneous, metamorphic, and sedimentary rocks, plus minerals, with the photos on this chart. Extra value on back: reproducibles, tips, and teaching information. 17" x 22". Sturdy and durable.
Carbonatites have > 50% carbonate minerals, and typically <10% SiO2. Most are shallow intrusive bodies of calcite-rich igneous rock in the form of volcanic necks, dikes, and cone-sheets in association with larger intrusions of alkali-rich silicate igneous rocks. Pahoehoe carbonite flow bounded by blocky lava levee. Note older lava, turned white by hydration.