This two-part article is based on Chapter 2 of the author's book <i>Gemstone Enhancement,</i> published by Butterworths in July, 1984. It examines the origins of gemstone treatment. Using such primary sources as Pliny's <i>History</i> and the relatively unknown <i>Stockholm Papyrus,</i> the author has uncovered many ancient references to, and even recipes for, the simulation or enhancement of gemstones. Among the processes described are crackling and dyeing quartz, foilbacking, the making of doublets and triplets, boiling amber in oil, and heat-treating sapphire to simulate diamond. Although some of the ingredients, such as goat's blood and leek juice, have been replaced by less exotic elements, it is interesting to note that through their crude experimentation, the ancient forerunners of modern science discovered basic methods and principles of gemstone treatment that are still in use today. -- AATA