gems, early lapidaries, Chrétien de Troyes lapidary, magical properties, medicine, carbuncle, emerald, beryl, corundum, history.1

Ruhe examines Chrétien de Troyes’s apparently anomalous use of emerald in Yvain, ou Le Chevalier au lion, where the perilous fountain has a pierced emerald block supported by four rubies. Medieval lapidaries, following Marbode, consistently attribute to emerald the power to avert storms and restrain lust, yet in Chrétien’s narrative the emerald is associated with precisely the opposite effects: the fountain produces violent storms, Yvain falls into passionate love and later madness, and other traditional virtues of emerald—revealing hidden things, foretelling the future, promoting eloquence, curing illness, and increasing wealth—are likewise systematically inverted. Ruhe argues that this is deliberate rather than an error or faulty recollection by Chrétien. Elsewhere Chrétien employs precious stones in ways consistent with lapidary tradition; the crucial distinction here is that the emerald is not worn on the body as a beneficial talisman but incorporated into a magical site. Its inverted powers therefore contribute to Chrétien’s ironic distancing from the supernatural traditions surrounding the fountain and perhaps also to a critique of knightly excess. The study demonstrates how close attention to medieval lapidary traditions can reveal a sophisticated literary play on the supposed virtues of gemstones in Chrétien’s work.