An 18-kt gold brooch, set with an opal and decorated with stylized embossed flowers with green enamel, designed by Bert Nienhuis (1873-1960) and made by goldsmith Lodewijk Willem van Kooten (1903-1972). Total weight approx. 6.3 g. H. 2.2 cm. L. 2.2 cm. A brooch with a nearly identical design by Nienhuis is on permanent display in Rijksmuseum Amsterdam (Collection no. BK-1980-67). Nienhuis’ jewelry designs are considered to be highlights of Dutch Art Nouveau. Literature Rijksmuseum: J.D. van Dam, J.J. Heij, 'Art Nouveau in het Rijksmuseum', p. 187, ill. 20;R.J. Baarsen, G. van Berge, 'Juwelen 1820-1920', p. 72-79, cat.no. 32f;H. Domisse et al, 'Klokken, zilver, sieraden uit de Nederlandse Art Nouveau en Art Déco 1900-1930', cat.no. 108;Bulletin van het Rijksmuseum 28 (1980), p. 134, ill. 4, cover.