Brad L. Cross, is widely recognized as an absolute authority on Mexican agates and is the author of the definitive work on the subject, “The Agates of Northern Mexico.” The 1996 book, The Agates of Northern Mexico is considered the “unrivaled standard work” on the subject and the only comprehensive documentation of the localities and history of these agates to date.

He is also the author of other books, including “Geodes: Nature’s Treasures,” and “Gem Trails of Texas.” He is currently working on two new books, “Mexican Agates: Majestic Treasures” and “Gem Trails of New Mexico.”

Brad has been a collector of museum quality agates for over 50 years. He has travelled extensively throughout northern Mexico and spent years conducting geologic mapping at a number of the agate occurrences throughout Chihuahua. He has also visited southern Brazil, evaluating the agate and geode deposits of the extensive Paraná flood basalts in the state of Rio Grande do Sul. He is a professional hydrogeologist and is currently employed with a consulting firm in Austin, Texas.

Publications:

Cross, Brad L., 1996, “The Agates of Northern Mexico,” Burgess Publishing, Edina, Minnesota.

Cross, Brad L., and Zeitner, June Culp, 2006, “Geodes: Nature’s Treasures,” Gem Guides Book Company, Baldwin Park, California.

Cross, Brad L., 2025, “Agate – Quartz Phenomenon,” Lithographie, Ltd., (One of several authors of the 2025 monograph.)

Cross, Brad L., 1996, “Zig Zags, Scallops, and Sunbursts,” Rock and Gem, Vol. 26, No. 11, (November 1996).

Cross, Brad L., 2000, “Agua Nueva Agate,” Rock and Gem, Vol. 30, No. 4, (April 2000).

Cross, Brad L., 2002, “The Coconut Geodes of Northern Mexico,” Rock and Gem, Vol. 32, No. 3, (March 2002).

Cross, Brad L., 2004, “Coyamito Agate,” Rock and Gem, Vol. 34, No. 3, (March 2004).

Cross, Brad L., 2005, “Alle Farben des Regenbogens – Die Mexikanische Achatstory,” Mineralien Welt, 16. Jg., Heft 5, (Sept. – Okt. 2005), pp. 65-72.

Cross, Brad L., 2005, “Achate Die Apache – Schleiereule,” Mineralientage München, Messethemenheft 2005, p. 38.

Cross, Brad L., 2008, “Classic Mexican Agate Deposits,” Mineralogical Record, Vol. 39, No. 6, (November-December 2008).

Cross, Brad L., 2014, “The Beauty of Agate,” MetaGuide Magazines, Fall Buyers Guide, Denver Gem & Mineral Shows, p. 46.

Cross, Brad L., 2025, “Nature’s Masterpiece: Uncovering the History of the Apache “Hooded Owl” Agate,” 3 pps.