Methods of opalizing glass were already known in sixteenth-century Venice, but their application to crystal (lead glass, developed in England in the seventeenth century) was invented in France in the nineteenth century. These two classical-inspired vases are made of opal crystal with two colors – gorge-de-pigeon pink and amethyst – and decorated with two chased and gilt bronze birds, carved in the round. The colors are typical of Restoration artifacts. The opacification was obtained using bone ash, pewter and arsenic; the pink was obtained with gold salts, and the purple with manganese oxide. French crystal opal pieces combining two colors were extremely rare in the early nineteenth century. The few known examples include those donated to the Musée de Sèvres in 1828 by the Bercy factory. The latter (1827-1867), founded around 1827 by the jeweler and goldsmith Jean Alexandre Paris, “maker of enamel for inlaying in crystal,” seems to have been the only factory to have combined two colors in simple designs or concentric zones, though colored opal crystal pieces were made by all the new French crystal glassworks – Le Creusot, Saint-Louis, Baccarat and Choisy-le-Roi. Nowadays it is very difficult to differentiate between the productions of these various factories. Opal crystal pieces became widely fashionable; they were primarily sold by the Parisian dealers centered around the Palais-Royal, many of whom also specialized in the production or adaptation of gilt bronze mounts. Most of the large opal crystal collections were formed during the second third of the twentieth century, when collectors of these typically French objects began to use the term “opaline.” This rare pair of Medici vases featured in several prestigious collections (such as the large Castille collection) before entering that of the donor. From 1935 on, several of these collections (including those of Mathilde Sée, William Odom and Mme King) were reassembled by the Musée des Arts Décoratifs, thanks to numerous gifts and bequests.
Yolande Amic, L’Opaline française au XIXe siècle, Paris, Gründ, 1952
Succession Castille, Versailles, Palais des Congrès, Jacques Martin and Olivier Desbenoit auctioneers, March 17, 1991, no. 149.