BOIVIN: PEARL AND AMETHYST 'NAIL HEAD' BROOCH, CIRCA 1930 The rectangular amethyst prism applied with a freshwater baroque pearl, between calibré-cut amethyst stepped shoulders, French assay marks, length 4.6cm 注脚 The nail-head design, that resembled a truncated pyramid, was originally inspired by the profile of a handmade wrought iron nail and was a motif employed and constantly modified by Madame Boivin. For further information and design drawings see Cailles, Francoise, "Rene Boivin Jewellery" (translated by Tanya Leslie), London, 1994, pp 124, 162.