The Cluny cross is a votive gift notable for its donor portrait and extensive narrative decoration, in niello, on the back. The front of the cross is much like those of the other four surviving silver and silver-gilt Middle Byzantine processional crosses with niello decoration that are regarded as belonging to the same group: all have repousse decoration on the front consisting of a central medallion from which rinceaux extend, forming a cross, and four medallions at the ends of the crossarms. The rinceau pattern on this example, a stiff, stamped version of the complex design that adorns the Cleveland Cross, indicates that the Cluny cross is one of the latest in date. Its central medallion is an image not of Christ Pantokrator, as on the other four crosses, but of the Virgin Orans. She is flanked by busts of archangels on the side arms, with Christ above and John the Baptist below, a variation on the standard Deesis iconography. The niello decoration on the back also focuses on the Virgin. At the center the Virgin stands holding the Christ Child (the Virgin Hodegetria); above is the Crucifixion with the Virgin and John the Theologian in attendance. The left arm depicts the Annunciation, with the archangel Gabriel approaching the seated Virgin. On the right arm and the foot are two scenes from the Protoevangelion of James, an apocryphal second-century text on the life of the Virgin that inspired much of the Marian imagery during the Middle Byzantine era. The damaged scene on the arm is of the Presentation in the Temple: the Virgin and her parents, Joachim and Anne, hands raised in supplication, approach the temple accompanied by a pair of candle-bearing maidens. A portion of the temple survives at the tip of the cross, but the figure of Zacharias receiving the Virgin is lost. At the base of the cross an angel descends to feed the Virgin in the temple, as described in the Protoevangelion. 
The representation of these scenes as separate events is typical of a Byzantine tradition that existed by the tenth century. By the twelfth century the official imagery of Constantinople had fused the scenes into a continuous narrative. One of the earliest examples of this innovation is found in the Menologion of Basil II. The use of the older tradition on the Cluny cross is evidence that the work was produced in a center relatively untouched by the artistic currents originating in the capital. A similar cross with narrative scenes in niello of the life of the prophet Elijah, now in the Musee d'Art et d'Histoire, Geneva, is reported to have come from Eskişehir in Turkey and provides a basis for the attribution of the four crosses to that region. Jean-Pierre Caillet and Jannic Durand agree that corruptions in spelling in the inscriptions support the attribution of these works to a provincial center, as would be found in northeastern Anatolia. Nevertheless, it remains difficult to confirm where any of these crosses were made or dedicated. At the foot of the cross is an image of the donor, the monk Kosmas, together with his dedicatory inscription — a rare combination that proves that the cross is a votive gift. Kosmas may have given the cross to a church dedicated to the Virgin or to a chapel in her name within a larger complex.