Relic of the Holy Nail with reliquary made c.980 AD in Trier. The reliquary was made under Archbishop Egbert (977-93) to enshrine the relic brought to Trier by Empress St. Helena in the 4th century. It measures 21.4 cm (8.5 in) long. The iron spike, said to be one of the four with which Christ was nailed to the cross, was a highly important relic in medieval Trier. It was carried in processions, used for swearing oaths, and is reported to have healed several blind people during one of its exhibitions. It was stored in St. Andrew's Altar and is displayed alongside it in the Treasury. Like St. Andrew's Altar, the reliquary made for the Holy Nail is known as a "speaking reliquary" because it is in the shape of the relic inside. The irregular shape of the nail would have provided a special challenge for the goldsmith but he did a magnificent job. He fashioned a square, tapering shaft decorated on each side with four gems and three enamel bands. The nail head is hinged so that the relic could be displayed and is also decorated with precious gemstones and enamel platelets. Some of the decorations have been lost over the centuries.