Vessel made up of four pieces of jasper and four silver gilt mounts. The body is formed by a piece of jasper with an oval section and semicircular profile, joined to its cover by a silver gilt strip. It has sixteen overlaid cameos, between which the same number of emeralds were originally intercalated. Three of these remain today. The rest of the mounts have a similar structure. The presence of Colombian emeralds and yellow jasper raises the possibility that it was made in a workshop outside the main Italian centres of Milan and Florence, and also outside the milieu of the French court. It is possible that it formed part of a set of vessels from Germany that was acquired by Louis XIV between 1684 and 1701, and probably consisted of pieces by Johann Daniel Mayer. Similar works are preserved in the Dauphin’s Treasure and at the Musée d’Histoire Naturelle in Paris.

Of the fifty-six emeralds that were counted on this cup in the 1776 inventory of the Real Gabinete de Historia Natural, only twenty-one are currently preserved. The vessel ended in a tall finial, lost in about 1813, which was also decorated with emeralds. Its form and volume are only known to us from the piece’s case. Of the forty cameos of different sizes that originally decorated the vessel according to the old inventories, thirty-six remain today. The state of the work in the 19th century can be seen through the photography of Juan Laurent y Minier, "Vase agate sardoine, montures d’or avec émaux et pierreries, XVIe siècle, règne de Henri II", c. 1879, Museo del Prado, HF0835/20.

The cameos, made of chalcedony, agate and onyx, the cameos have some motifs that are repeated elsewhere, such as the woman with the bare breast, who also appears on other pieces at the Prado like the casket O31. The repertory is completed by three heads with no distinctive features, three cameos with marine horses and a dolphin, a head of an emperor crowned with laurel, two busts (one of a woman with her hair loose), a reclining figure, and some cameos extracted from other series. Mythologically inspired scenes include the satyr contemplating Hermaphroditus, a horseman riding through flames, Fame or Venus in triumph, a libation before an altar and a figure with a prisoner, Orpheus pacifying Cerberus, and Hercules fighting the Nemean lion. As Angulo pointed out, the cameos are fairly crude and seem to come from semi-industrial series. The same is true of the mount of the vessel, fashioned with basic techniques but balanced in its composition if the volumes of the cover are taken into account (L. Arbeteta, in press).