Jewellery, Watches and Objects of Vertu to include the personal archive of Louis Osman, goldsmith and architect

An Italian gold, micro-mosaic and white enamel quatrefoil brooch, circa 1854-58, by Castellani, the central circular turquoise-blue micro-mosaic panel with inlaid silver wirework depicting the Chi-Rho monogram, within a quatrefoil surround with raised borders, decorated with sky-blue and white enamel, granulation and ropetwist detail, mounted in yellow gold with bloomed finish, with Castellani maker’s mark, (monogram in lozenge cartouche), to the reverse, width 39mm. £2000-3000

The Castellani family, of Fontunato Pio and his sons Alessandro and Augusto were the pre-eminent jewellers in Rome throughout the mid 19th century. They were inspired by the archaeological excavations and discoveries occurring in Italy at this time and their bold designs looked to classical and medieval sources for inspiration, celebrating their country’s cultural heritage.

By the 1840’s the once popular trend for micro-mosaics was waning, but in 1852 the Castellani family, together with the Duke of Sermoneta, had the idea of combining micro-mosiacs with goldwork to reinvigorate the art form. They returned to the traditional micro-mosaic form of using regular square-shaped tesserae in single or two-contrasting colours, with the surfaces left unpolished so that the tesserae, all at slightly different angles, catch the light as the originals would have done in the walls of churches. They also introduced the novel feature of including gold or silver wires (or fettucine) within the mosaic itself.

The Chi-Rho monogram is the Christian symbol for Christ, also called the Constantinian, composed of the entwined Greek letters X (Chi) and P (Rho). The monogram is flanked by the smaller Greek letters Alpha and Omega (signifying the beginning and the end). It is a reference to the appellation of Christ given in the Book of Revelations 1:8, ‘I am the Alpha and Omega’.

See: Soros, S. W. and Walker, S. (ed), Castellani and Italian Archaeological Jewellery, Yale University Press and the Bard Graduate Centre for Studies in Decorative Arts, Design and Culture, 2005, chapter 6 and page 334, figs 6-17 and for a similar example to the above brooch, see fig 13-3 (in private collection).