An 18K yellow gold plique-á-jour enamel butterfly brooch with ruby eyes.
In French, plique-á-jour means, ‘open to the day’. It is a type of enamel in which a design is outlined in metal, filled with enamels and fired. The ground plate is removed after the firing, leaving behind a translucent enamel that resembles stained glass. It is very fragile and few pieces remain fully intact today. It is an ancient technique revived during the Art Nouveau period.