Thistle Aigrette Brooch. Late 19th century, Boucheron, A diamond-set brooch, in the form of a thistle aigrette and pave-set throughout with diamonds, mounted in silver and yellow gold. Frédéric Boucheron was awarded Grand Prix for his stand at the Exposition Universelle of 1878. Much acclaimed was this aigrette. The thistle motif, later associated with the Art Nouveau jeweller René Lalique, was new, for most naturalistic jewels were version of the popular rose, lily, lilac and oak leaf.