The rectangular box rests on four detachable lobed feet. The box has broad cast moldings above and below with a string of beads around the top and bottom edges. The sides of the box are formed of square panels of intricate geometric ornament in low relif- four across the front of the box and three along the sides. The box has two covers assembled on one hinge; the interior cover may be concealed within the outer cover by a separate lock. The square panels on the hidden cover are of a different geometric design, incorporating an interlaced chain with an inscription and at the center initials in cipher. The panels, separated by plain moldings, are cast individually from a model that was pierced and assembled. They are meticulously finished.

This elaborate casket, a tour-de-force of goldsmithing techniques, was probably designed and commissioned by English collector and connoisseur William Beckford as a gift for his Portuguese companion, Gregorio Franchi. The two collaborated on the design of many original works of art, using a variety of historical sources. The exterior panels show the influence of Islamic geometric ornament, while the panels on the inner lid are based on interlaced knot motifs.