Vessel made up of two pieces of hardstone and three enamelled gold mounts. The larger piece forms the deep boat-shaped bowl, with the front raised, leaves on the rim, and a volute at the rear. A high S-shaped handle curves above the mouth and is connected to the body with a rectangular brooch-like appliqué. The bowl is joined with ring mounts to the short moulded stem, which ends in a flat oval foot with another ring mounted around the edge. The designs of the enamelling consist of jasmines, volutes and ribbons in black and white with touches of blue, all opaque. Following the description in the Spanish inventories, Angulo pointed out that the piece resembles a helmet when inverted, and was therefore formerly called a "morion". However, as Arbeteta emphasised, it repeats a model for a ewer that was very frequent in the Netherlands, where a similar design continues to be produced today.

As an example of the difficulties involved in identifying hardstones, this vessel was considered to be of oriental agate in the 1689 Versailles inventory; of oriental diaspore when described in 1776 by the Real Gabinete de Historia Natural; of yellowish agate with veins of oriental cornelian according to the Governing Committee of the Museo de Ciencias Naturales in 1839; of chalcedony with cornelian veins in the gemological study of 1989; and of jasper in the study carried out at the Restoration Workshop of the Museo Nacional del Prado in 2017.

Arbeteta noted that the design of the vessel is undoubtedly related to forms from classical Antiquity, filtered through the most imaginative designs of Enea Vico as reinterpreted by numerous followers such as Cornelis Floris, who published vessels with a certain similarity in their volumes in 1548. This piece is related to the curved and hull-shaped forms typical of the production of the Prague workshop of the Miseroni, whose director, Ottavio, preferred designs for vessels with volutes and large smooth surfaces, though with certain elements in relief that give the object an organic appearance. The short-stemmed foot is also a frequent model in the Miseroni workshop. Distelberger related this piece to a later vessel preserved at the Kunstkammer of the Kunsthistorisches Museum, inv. 1640, which he considered to be by the hand of Ottavio. It is very similar in its strange shape, though prepared in this case for a stem or foot to be fitted. The mounting, Italian rather than Central European in taste, also seems to indicate the same provenance. The closest visual parallel to this piece is the common form of domestic ewer or jug that is still found in the households of Holland and Belgium, generally made of copper. The model is certainly an old one, and suggests a use of similar designs in the Netherlands that may be extendable to Central Europe.

The state of the work in the 19th century can be seen through the photography of Juan Laurent y Minier, Untitled, c. 1879, Museo del Prado, HF0835/54.