Handbook of Gemstone Carving by Ed and Leola Wertz was copyright 1968, with revisions in 1994, and containes 47 pages with a complete guide to the materials, equipment and techniques for carving gemstones.  Some of the articles cover: ideas for subjects to carve, carving forms and finishes, how to carve a leaf, carving in the round, portraits in stone, notes about display and much more.