Uvalde County is located in southwestern Texas, including part of the north margin of the Gulf Coastal Plain and the south margin of the Edwards Plateau. Its principal mineral resources are asphalt rock, clay, limestone, gravel, trap rock, and surface and underground water.

Travis County is located on the Colorado River at the west or inner margin of the Gulf Coastal Plain. Its principal mineral resources are clay, limestone, sand and gravel, surface and underground water, and possibly petroleum.

Bell County is partly within the Gulf Coastal Plain and is crossed by the Balcones zone of faulting. West of this fault zone, the surface formations are those of the Comanche Cretaceous, while to the east of the fault zone, the formations are largely those of the Gulf series or Upper Cretaceous.

Bastrop County is located on the Colorado River near the west margin of the Gulf Coastal Plain. Its principal mineral resources are clay, lignite, sand and gravel, petroleum, and surface and underground water. The Missouri, Kansas, and Texas and the Southern Pacific railroads cross the county.

During the latter part of 1930, several wells were drilled into serpentine in the vicinity of Kimbro in Travis County. One of these, on the Allen farm, drilled in December 1930, is reported to have obtained oil in commercial quantities.

The following list of common minerals and mineral products has been prepared by the Bureau of Economic Geology of the University of Texas as a brief index to the mineral resources of Texas.