Frac Sand, McCulloch County, Texas
Mineral: Proppant Frac Sand (SiO2) Location: Fairmont Santrol mine in Voca County: McCulloch County, Texas Chemical Formula: Quartz Sand (SiO2) Other interesting facts: Details in: Kyle, J. R., and E. F. McBride. "Geology of the Voca frac sand district, western Llano uplift, Texas." Proceedings of the 48th Annual Forum on the Geology of Industrial Minerals: Arizona Geological Survey Special Paper. Vol. 9. 2014.