The corpus as a genre of art-historical writing has served students of Carolingian art particularly well. Adolph Goldschmidt set an exceptionally high standard in 1914 with the first volume of his Die Elfenbeinskulpturen aus der Zeit der karolingischen und saechsischen Kaiser, a standard matched by Goldschmidt's most important followers, Wilhelm Koehler and Florentine Muetherich, with their Die karolingischen Miniaturen (begun 1930; the most recent installment, the first part of volume 6, appeared in 1994). Given this tradition, it is a pleasure to report that Genevra Kornbluth's Engraved Gems of the Carolingian Empire is a worthy successor to these earlier corpora.
In certain ways, Kornbluth's task was easier than that of her predecessors. The 20 extant Carolingian engraved gems make up a body of material far smaller than the hundreds of Carolingian ivories or illuminated manuscripts. But Kornbluth also faced difficulties greater than those that confronted Goldschmidt, Koehler, and Muetherich. As most scholars will know, the Carolingian gems are often difficult to make out, even in person, and have not, until now, been photographed well. We must, therefore, be exceptionally grateful that Kornbluth had the perseverance to obtain permission to photograph each of the gems herself. As a result, in the book each gem is documented by at least two, and usually more images (there are a remarkable 27 of the Lothar crystal). These photographs almost always include life-size depictions of the gems and a side view, as well as full details of any significant figures. Thanks to these photographs alone it is hard to imagine Kornbluth's book being surpassed as a reference work in the foreseeable future.
Engraved Gems of the Carolingian Empire follows very much the type of organization established by the corpora of Goldschmidt and Koehler and Muetherich. An introductory chapter discusses how the gems were made, gives an overview of the subjects depicted on them, emphasizing how subject matter and material are often closely related, and surveys the distressingly meager information we have as to the function of these gems. Kornbluth's main contribution in this chapter is to establish how unusual are the Carolingian engraved gems. She is entirely convincing that technical differences in the cutting of Carolingian and Byzantine gems indicate that the Carolingians did not learn their craft from Byzantine artists, as had previously been thought. There are no medieval Western carved gems before the ninth century, and Kornbluth plausibly proposes that the Carolingians derived their method of carving gems from the essentially identical techniques used to make the dies needed to stamp coins.
The rest of the book is devoted to a catalogue of the gems themselves. The grouping is stylistic. All of the gems are divided into two groups, the "lentoid" and the "cabuchon" (although this division literally refers to the shape of the crystal, Kornbluth makes clear that it also demarcates significant stylistic groups), which are further subdivided into smaller groups around important crystals (e.g., the Susanna Group). Each gem is treated separately, with the length of the entry determined primarily by the iconographic complexity of the carving (the Lothar Crystal, called by Kornbluth the Susanna crystal, receives 18 pages; other gems get a page or less).
Kornbluth's stylistic groupings seem to me unobjectionable, although I am skeptical that they are a particularly useful organizing structure for her catalogue. What is objectionable, particularly in what will surely become a standard work of reference, are some of the conclusions about date and patronage she draws from the stylistic evidence, conclusions that seem to me to be based on a model of artistic production that is not that of the Carolingian period. For example, Kornbluth convincingly attributes the patronage of the Lothar crystal to the circle of Lothar II and so dates it to the years of that king's reign, 855-869. She then attributes three other crystals (the Baptism in Rouen and the Crucifixions in Paris and Milan) to the maker of the Lothar crystal. So far, so good. But in her catalogue entries for the latter three crystals, not only are they assigned the precise dates of the Lothar crystal (not even a properly hesitant "circa" is appended to "855-69" in the catalogue entries), but it is suggested that all three were "probably made for Lothar II." This conclusion is unsupportable. Unlike the Lothar crystal, the iconography of the Baptism and Crucifixion crystals is not particularly royal. Furthermore, just because a royal patron ordered an object from a workshop, it certainly does not follow that all products of that workshop were made for the same royal patron. As counter examples one might cite Tours, which simultaneously made manuscripts for Lothar I and for Charles the Bald; St. Amand, which made one manuscript for Charles the Bald and many manuscripts for other, non-royal patrons; or even Charles the Bald's so-called "court school," which seems not to have worked exclusively for the king.
Catalogues demand an exceptionally high standard of scholarly care and tact. Kornbluth meets the first criterion admirably; I found remarkably few mistakes in the book 1. Her tact occasionally can be called into question, as when she pushes her evidence too far. Examples are the dating issues raised in the last paragraph or Kornbluth's interesting but rather wild claim that the unusual Remiremont gem "probably had a secular use, as a token of identification presented by the bearer when communicating messages from a superior." Kornbluth's arguments about this gem are ingenious, but I think "probably" is too strong a word to describe the results. The Remiremont stone does illustrate one of the most interesting aspects of some of these gems: their iconography is related to the material of which they are made. The Remiremont gem, for example, is unique in the Carolingian corpus in two ways: it is made of agate and depicts a ship. Kornbluth convincingly connects these two points, for she discovered that agate was believed to control the malevolent powers of water. In other instances, for example those crystals depicting the Baptism and St. Paul, Kornbluth was able to show how late antique and Carolingian exegesis connected those subjects with the material nature of crystal. As Kornbluth puts it, in these cases "the material completes the meaning of the image." Are there comparable instances of such a symbiotic relationship between art and material elsewhere in the Carolingian period? We do not find out in this book, not, I think, because Kornbluth is uninterested in that question, but because her chosen catalogue format really does not provide a forum to explore the broader issues raised by her material. Thus, the arguments relating material and iconography appear scattered across various entries, rather than grouped together where they might be mutually supporting.
Perhaps in a more synthetic article Kornbluth will be able to pursue some of the interesting questions that did not fit well into her book. No single book can satisfy every need and we should by no means regret that Kornbluth chose to produce a catalogue, for like her predecessors Goldschmidt, Koehler, and Muetherich, Kornbluth has produced a book that will stand scholars in good stead for many years to come.