SELECTED REFERENCES

Anderson, B. W. (1948) Gem testing: Emerson, New York.

Baker, C. L. (1935) Metallic and non-metallic minerals and ores (precious stones), in The geology of Texas, Vol. II, Structural and economic geology: Univ. Texas Bull. 3401, Jan. 1, 1934, pp. 568-569.

Barnes, V. E. (1940) North American tektites: Univ. Texas Pub. 3945, Dec. 1, 1939, pp. 477-582.

Dake, H. C., Fleener, F. L., and Wilson, B. H. (1938) Quartz family minerals: Whittlesey House, McGraw-Hill Book Company, Inc., New York.

Ford, W. E. (1932) A textbook of mineralogy (4th ed.): John Wiley and Sons, Inc., New York.

Kraus, E. H., and Slawson, C. B. (1947) Gems and gem materials (5th ed.): McGraw-Hill Book Company, Inc., New York.

Kunz, G. F. (1892) Gems and precious stones of North America (2d ed.): Scientific Publishing Company, New York.

Pough, F. H. (1953) A field guide to rocks and minerals: Houghton Mifflin Company, Boston.

Simpson, B. W. (1958) Gem trails of Texas: Granbury, Texas.

Sinkankas, John (1955) Gem cutting: D. Van Nostrand Company, Inc., Princeton, New Jersey.

—— (1959) Gemstones of North America: D. Van Nostrand Company, Inc., Princeton, New Jersey.

Smith, G. F. H. (1958) Gemstones (13th ed.), revised by F. C. Phillips: Methuen and Company, Ltd., London.

Sperisen, F. J. (1950) The art of the lapidary: The Bruce Publishing Company, Milwaukee, Wisconsin.

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.

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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.

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Plate II

A Gem-quality garnet crystals and faceted gem from Gillespie County, Texas. Natural size.

B Labradorite from Brewster County, Texas. Both stones are pale yellow. One and a half times natural size.

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Plate III

A Pink microcline crystal from Burnet County, Texas.

B Smoky quartz from Burnet County, Texas. Natural size. Colorless crystal at center back is included for color comparison.

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Plate IV

Polished agate from gravels of the Rio Grande near Zapata, Zapata County, Texas. Bands are blue and gray; other inclusions are brown, yellow, and reddish. One and a half times natural size.

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Plate V

A Texas tektites (bediasites) showing variety of surface features. Natural size.

B Topaz crystal from a pegmatite dike near Streeter, Mason County, Texas. Natural size. Measurements: 1½ by 1⅝ by 3 inches; weight: 194 grams (970 carats); pale blue; mostly gem quality.

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Plate VI

A Topaz from stream gravels near Streeter, Mason County, Texas. Natural size. Left to right: colorless worn pebble; emerald-cut pale-blue topaz, weight 10 carats; pale-blue worn pebble, weight 205 carats; step out sky-blue topaz, weight 13 carats; pale-blue worn pebble.

B Tourmaline crystals in schist from Llano County, Texas.

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