Phosphatic Sandstone, Bexar County, Texas
Location: listed as 7 miles west of San Antonio on Castroville Road on banks of Leon Creek
Chemical Analysis lists samples as 3 to 18% Phosphoric Acid (see ref. below)
Specimen Size: 2.25 x 2.25 x 1 inches
Specimen Weight: 100 grams
in the Jackson School Collection at the University of Texas at Austin.
Collection Reference: TMM2732.
Additional Information: Numerous references to phosphatic sandstone at this location, including:
Bulletin of the University of Texas No. 365, Scientific Series No. 29, October 15, 1914, "The Mineral Resources of Texas", by William B. Phillips
(available online at: https://books.google.com/books?id=ma1RAAAAMAAJ)