Within Catalan Gothic precious metalwork the shape and the proportions of the Saint Lawrence reliquary casket correspond to a type of composition that, on a different scale, was also used in the making of Eucharistic ciboria and boxes. The structure of the reliquary is a rectangular body with a four-sided lid, slightly truncated and crowned by a hexagonal shaft where a cross, now lost, must have been fixed, and it stands on four small gilt-carved lions at the corners. The silverwork, white and gilt, is attached to the wooden box which constitutes the core of the piece and shows on the sides floral decoration of twisting vine shoots with gilt vine leaves, almost circular, moulded to the transparent enamelled plates, and the original lock that is in a central position. Three quatrefoil enamellings, inscribed in a square, occupy the centre of the side and, at the same time, confer on it a religious content. On the lid, on a reticulate blue ground, Jesus, the Son of God, with a red cross-shaped halo, seated and dressed in a violet-pink tunic and an emerald green cloak with golden yellow edges, is blessing and showing the book of the law. On the front plate, the Virgin enthroned and Saint Lawrence present the same range of colours. These enamellings with refined carving, composition and chromatic quality, are clearly Italian in style, to be precise that of Tuscany, and, yet, the models have parallels with the work conserved of Ferrer Bassa, the Barcelona painter, and his workshop. The casket is marked with several stamps identifying the Barcelona workshop.