Igneous+Rocks


 * Igneous Rocks are rocks formed by cooling and solidification of a melt.**

__Intrusive__-Igneous rocks that were formed from cooling of magma beneath the earth's crust.

__Extrusive__-Igneous rocks that were formed from cooling of lava above the earth's crust.

__Mafic__: These rock s are dark in color and high in density.

__Felsic__: These rocks are light in color and low in density.

If the texture is smooth then the rock formed quickly above ground, but if the texture is coarse grained then the rock formed slowly below ground.
 * This is the Sedimentary Rock page from the Earth Science Reference Tables:**

Note: No igneous rocks contain calcite, which in turn means no igneous rocks react to hydrochloric acid.