Texas Rocks and Minerals

Texas Rocks and Minerals, subtitled An Amateur's Guide, is by Roselle M. Girard, with sketches by Bill M. Harris. The contents cover what rocks and minerals are, chemical elements, igneous rocks, sedimentary rocks and metamorphic rocks, with static, contact and dynamic metamorphism.

The guide says those who study fossils are called paleontologists, those who study minerals are called mineralogists, and those who study rocks are called petrologists. The great divisions of geologic time, called eras, are Early Precambrian, Late Precambrian, Paleozoic, Mesozoic and Cenozoic, divided into smaller units of time called periods, which are divided into epochs. Texas State Capitol building at Austin is made of Burnet County granite obtained from Granite Mountain near Marble Falls, Texas. Granites also appear at the surface in the Trans-Pecos country of west Texas, in areas that include the Franklin Mountains of El Paso County, the Quitman Mountains of Hudspeth County and the Chisos Mountains of Brewster County.