In his Paedagogus, written at the turn of the second and third centuries, Clement of Alexandria spoke in explicit favour of seal stones (3.59.2). Although Clement deemed most images problematic (‘empty idols’), gold finger-rings were a practical necessity. While banning certain sorts of engraved subjects (‘faces of idols’, ‘the sword or bow’, ‘drinking cups’), moreover, Clement actively encouraged others — a dove, fish, ship, lyre, anchor, or fisherman. Clement ascribes a symbolic function to such images: according to this rhetoric, the impressed image of a man fishing could ‘call to mind [memnêsetai] the apostle and the children drawn out of the water’.

Given the evident importance of such imagery to early Christian apologists, it is perhaps surprising how little attention has been paid to the corpus of extant early Christian intaglios, cameos and rings. As the introduction to this book surveys, scholars have conspicuously undervalued this material (in his magisterial three-volume work on Die antiken Gemmen, for example, Adolf Furtwängler dedicated a mere dozen pages to the productions of later antiquity). Quantitatively speaking, such neglect is perhaps understandable: although over 100,000 extant gems date between Augustus and Aurelian, only a 1,000 or so can be assigned to later antiquity — ‘a certain indication that the use of engraved gems declined rapidly after the mid-third century’ (11). For all their diminutive number, though, early Christian gems possess a disproportional importance for those interested in late antique visual culture, or indeed the history and theology of the early Church. Spier's book — with its excellent black and white plates (155 in total) — makes the material properly accessible for the first time.

The catalogue and discussions are deliberately wide-ranging. S. discusses some 1,000 gems, in addition to 144 ‘misattributed, forged and uncertain works’ (not all of them photographed), 100 engraved rings (a selective survey), 30 lead sealings, and 39 homogeneous jasper gems with Christian monograms. Apart from the introduction and three appendices (on rings, lead sealings, and jasper gems), there are seventeen chapters in all, divided chronologically, thematically and geographically (‘The Good Shepherd’, ‘The Garnet Workshop and Glass Intaglios, Late Fifth Century’, ‘Christian Gems in the Sasanian Empire’, etc.). Six indices and concordances round off the catalogue, collating individual collections, provenances, materials, iconographic subjects and inscribed texts.

Each chapter begins with an introductory overview, then a taxonomic survey-cum-catalogue, and finally a series of collective and thematic discussions. In each case, it is the depth and breadth of S.'s learning that will most impress. As explained on pp. 12–13, it is not always easy to attribute or date these objects. In each case, though, the evidence is laid out according to a special framework of shapes and materials (12, chart 1). S. is also concerned to contextualize the engraved iconography; he discusses each individual gem or type in light of its larger visual context, and across an array of different artistic media.

As the price suggests, the book is clearly intended for a specialist audience. Still, it also caters to an array of different scholars — not just those interested in gem production per se. For this reviewer, it is the corrective to standard accounts of early Christian iconography that most stands out. So it is, for example, that we find scenes of the crucifixion on gems dating even as early as c. a.d. 300, preceding almost all other extant representations (were miniature cameo depictions somehow less irksome?); some of those depictions fly in the face of Scriptural accounts (Christ crucified in the presence of the twelve apostles, for example), and another depicts Jesus naked (no. 443). Equally important is the fifth chapter, which demonstrates the continuities between gems of the Graeco-Roman kriophoros type and Christian depictions of the Good Shepherd; earlier in the book, we also read about the history of the engraved chi–rho monogram in the East (which appears long before Constantine's apparition after the Battle of Milvian Bridge (32–4)). Other conclusions concur with what can be gleaned from the earliest catacomb paintings and sarcophagi reliefs: the preference for Old over New Testament themes in the third and fourth centuries (ch. 6), for example, or the appropriation of other pagan symbols and ideograms (ch. 3).

Different chapters will appeal to different scholarly interests. Quite apart from the important chapters on Christian magical gems, the distinctive traits of Syrian-Palestinian gems, and later rock-crystal pendants, the sixteenth chapter on Jewish seals will be of particular importance. As S. points out, gems seem to have negotiated broader Judaic prohibitions against gentile idolatry (hence those intaglios which depict Old Testament subjects complete with Hebraic titles or texts). For Jews, as for Christians, these objects seem to have been associated with a special visual status or ‘ontology’ — providing not only inscribed miniature images, but also (when used as seals) impressed representations after each impressed engraving. It is Judaic Scripture, after all, which gives us the mantra, ‘set me as a seal upon thy heart’ (Solomon 8:6).

Such broader questions about the special status of gem imagery are somewhat ill-served by the catalogue genre. The aim of his book, S. writes, is to ‘provide a basis for the further study of what is in fact a fairly substantial body of material pertaining to late antiquity, early Christianity and Judaism’ (9), S.'s volume more than fulfils that remit. But the task now is to rethink how these little objects relate to larger Christian discourses of representation and replication — discourses that were at once constructed and reflected by images and texts alike. Within that grander intellectual historical project, S.'s excellent compendium will prove an indispensable first resource.