ALLAN W. ECKERT, PhD, has been a professional writer for over thirty years, with more than thirty--seven books to his credit. He is the recipient of an Emmy Award for outstanding program achievement, and his short stories have earned him seven Pulitzer Prize nominations. A member of the American Society of Gemcutters, Dr. Eckert has mined opals in Virgin Valley, Nevada, as well as at the New Coocoran Opal Field of Lightning Ridge and the White Cliffs Opal Field, both in New South Wales, and at the Yowah Opal Field in southwestern Queensland. Over the past six years, he has cut and polished over 4,000 opals and faceted hundreds of other gemstones. His previous publications include the four--volume set Earth Treasures, a guide to rock dig locations in the United States.