gems, glyptic, engraved gems, agate, cameo, intaglio

Riederer provides the mineralogical identification of the materials used for the engraved and magical gems catalogued by Hanna Philipp in Mira et Magica. The contribution supplies the scientific basis for distinguishing the various natural stones and artificial materials represented in the collection and discusses the problems inherent in identifying ancient gem materials, particularly where traditional archaeological or gemological names do not correspond precisely with mineralogical nomenclature. The results complement Philipp’s archaeological and iconographic catalogue by establishing the actual materials from which the objects were made. A later archaeometric discussion specifically uses the Mira et Magica collection to illustrate how different investigators could arrive at differing identifications because of both analytical and nomenclatural problems.