Granite

Granite is an intrusive igneous rock. Intrusions (plutons) are bodies of igneous rock that result from crystallization of magma deep underground. Slow cooling at depth in the Earth produces larger crystals (coarse grained) that can easily be seen by the unaided eye.

Granite is generally light colored in shades of white, grey, or pink. Minerals are mostly quartz and feldspar, with small amounts of mica (muscovite or biotite).

Granite in Texas is found in the Llano Uplift of Central Texas and the Trans-Pecos of West Texas.

The Town Mountain Granite, the most famous granite in Texas, was used to construct the State capitol building, as well as many other State office buildings in Austin. Granite in Texas is quarried for building stone and aggregate.

The granite sample found in the Texas Rock Kit was collected from the Llano Uplift and is Precambrian in age.