In my opinion, this is the most important piece that will be auctioned by Sotheby's London next wednesday, December 14th. It is a brooch made by Boucheron in the 1890's depicting a cicada with the most exquisitely made wings in plique-à-jour enamel and calibre cut sapphires. The head and the body are set in diamonds and sapphires as well and the eyes are set with two cabochon cat's eye crysoberyl.
Frederic Boucheron opened his first shop at the Palais Royal in Paris in 1858. He was admired and reputed amongst his contemporary jewellers for his superb craftsmanship, his daring designs and imagination and his selection of only best stones. The brooch above was made many years before the Art Nouveau movement started in Paris, Boucheron breaks here with the formalities in fine jewellery imposed by the Belle Epoque and the Garland style and turns a daily insect into the finest piece. This is a true predecessor of the style both for the technique as well as for the naturalistic motif.
Plique-à-jour (French for "letting in daylight") is a vitreous enamelling technique where the enamel is applied in cells, similar to cloisonné, but with no backing in the final product, so light can shine through the transparent or translucent enamel. It is in effect a miniature version of stained-glass and is considered very challenging technically: high time consumption (up to 4 months per item), high failure rate, requires psychological strength to start over. The technique is similar to that of cloisonné, but using a temporary backing that after firing is dissolved by acid or rubbed away. The technique was developed in Byzantine Empire in 6th century AD and was revived in the late 19th century movement of revivalist jewellery, and became especially popular in Russia, Scandinavia and in the French Art Nouveau.