gems, glyptic, engraved gems, agate, cameo, intaglio, Greece, history of gemology, treatments, alchemy

Berthelot and Ruelle assemble, edit, translate, and interpret the surviving Greek texts relating to ancient alchemy, providing one of the fundamental source collections for the history of early chemistry. The work includes Greek texts with French translations and extensive commentary on the techniques, substances, apparatus, and theories described by Greek and Byzantine alchemical writers. Of particular gemological interest are passages dealing with minerals, metals, coloring processes, and the artificial production or imitation of precious materials, including recipes intended to give stones the appearance and colors of emerald, ruby, sapphire, and other gems. The collection is especially important for documenting ancient methods of dyeing, staining, and otherwise altering stones and glass, and for tracing the relationship between practical craft recipes and the developing theoretical traditions of alchemy.