The acicule, or pins for Pallium, are the elements that characterize the Metropolita Bishop. The pallium, made of white wool, is the symbol of the bishop as the "Good Shepherd" and, at the same time, of the Lamb Crucified for the salvation of the human race. The pins remember the nails of the Crucifixion and, over time, they became important decorative elements and, sometimes, real jewels.