Sterrett, D. B. (1913) Gems and precious stones, in Mineral resources of the United States, Calendar Year 1912, Part II, Non-metals: U. S. Geol. Survey, pp. 1023-1060.
[Plate I]
A
Gem-quality celestite crystals from Travis County, Texas. Twice natural size. Lower portion of the crystals is colorless; the tips are dark blue.
B
Opalized wood from the Texas Gulf Coastal Plain. Specimen at left is rich brown and tan; specimen at right is fossil palm wood and is black, reddish brown, and white. One-third natural size.
[Plate II]
A
Gem-quality garnet crystals and faceted gem from Gillespie County, Texas. Natural size.
