corundum, synthetic corundum.7, gems

Johann Kunckel’s Ars vitraria experimentalis, oder vollkommene Glasmacher-Kunst is an expanded German edition and experimental commentary on Antonio Neri’s L’Arte vetraria, incorporating Kunckel’s own extensive practical experience in glassmaking and chemistry. The work describes the preparation of glass, furnaces, raw materials, coloring agents, purification, crystal glass, enamels, artificial gems, and numerous specialized glass compositions, while critically testing and supplementing Neri’s recipes. Of particular interest to gemologists are its methods for producing colored glasses and imitations of precious stones, including materials intended to resemble ruby, sapphire, emerald, and other gems. Kunckel’s emphasis on experiment and reproducible workshop practice makes the work an important source for the history of glass technology, synthetic gem imitations, and the transition from alchemical craft traditions toward experimental chemistry in the late 17th century.