Gems of heaven publishes 30 of the 34 papers presented at the British Museum Byzantine Seminar held in May 2009 on the subject of engraved gemstones in late antiquity. Other than J. Spier's Late Antique and Early Christian gems 1 and several studies of magical gems (many of which are of this period), 2 glyptic scholars have not paid as much attention to late antiquity as to earlier periods. Gems of heaven focuses on both intaglios and cameos and covers the broad range of cultural contexts present in late antiquity -Greek, Roman, polytheist, Christian, Jewish, Sassanian, East, West. The paper topics run the gamut from iconography and style, to the function and re-use of gems, to scientific analyses and methodological concerns. Contrary to the book's title, the chronological scope of the papers extends before and stretches beyond late antiquity, and the subject matter encompasses more than engraved gemstones, but this range allows the reader to gain a refreshingly broad perspective on the value of gemstones in antiquity and their treatment in modern scholarship. The papers are also remarkably well illustrated, with numerous colour photographs; only in a few is the lack of a particular image felt.Conference papers tend to fall into three categories: those that argue a thesis; those of the 'show-and-tell' variety; and those that explore a particular topic and serve as a 'call to arms' (e.g., in support of the adoption of a particular methodology). All exist here, but every paper contributes to the value of the whole, whether by elucidating our knowledge of gems' physical characteristics, increasing our understanding of how they relate to broader social and cultural issues, or contributing to new methodologies and scientific techniques for analyzing them.I will give a brief overview of each and then comment on how they work together to reveal the richness of the field and the new directions open to it, as well as the primary issues it faces.The collection begins with papers focusing on gemstone materials and the use of non-destructive scientific analyses. These are applicable to gems of any period or cultural context. In "Non-destructive gemmological tests for the identification of ancient gems", Ç. Lüle advocates the use of archaeogemology, a multidisciplinary approach which incorporates elements of gemology, archaeology, and geology to identify the mineralogical and geographical origins of gemstones in order to integrate this information into broader archaeological inquiries (e.g., on migration or trade routes). He also addresses 1 Published in the series "Spätantike, frühes Christentum, Byzanz. Reihe B, Studien und Perspektiven 20" (Wiesbaden 2007). 2 E.g., C. Bonner, Studies in magical amulets, chiefly Graeco-Egyptian (Univ. of Michigan Studies, Humanistic Series 49; Ann Arbor 1950); C. Faraone, Vanishing acts on ancient Greek amulets: from oral performance to visual design (BullInstClassStudLon 115, 2012); A. Mastrocinque (ed.), Gemme gnostiche e cultura ellenistica: atti dell'incontro di studio, Verona 1999 (Bol...
