is a rock that is composed primarily of calcium carbonate. It can form organically from the accumulation of shell, coral, algal and fecal debris. It can also form chemically from the precipitation of calcium carbonate from lake or ocean water. Limestone is used in many ways. Some of the most common are: production of cement, crushed stone and acid neutralization.
is a fine-grained, extrusive igneous rock composed mainly of plagioclase with other minerals such as hornblende, pyroxene and biotite.
is a fine-grained, dark-colored extrusive igneous rock composed mainly of plagioclase and pyroxene
is a coarse-grained, intrusive igneous rock that contains a mixture of feldspar, pyroxene, hornblende and sometimes quartz.
is a coarse-grained, dark colored, intrusive igneous rock that contains feldspar, augite and sometimes olivine
is a coarse-grained, light colored, intrusive igneous rock that contains mainly quartz and feldspar minerals.
is a coarse-grained intrusive igneous rock that is composed almost entirely of olivine. It may contain small amounts of amphibole, feldspar, quartz or pyroxene