A peculiar kind of decoration which is specially characteristic of the early Irish ecclesiastical metalwork consists of plates perforated with triangles, squares, and crosses, so as to form a geometrical pattern. The plates are usually of bronze covered with silver, and the contrast between the bright surface of the white silver and the pierced portions through which the dark bronze below can be seen gives the general appearance of chequerwork. There are good instances of this class of decoration on the Shrine of the Bell of St. Patrick’s Will, and the Cumdachs of Dimma’s Book, the Stowe Missal, and the Shrine of St. Mogue. Cruciform pierced work of a similar kind also occurs on an ivory of the tenth century representing the raising of the widow of Nain’s son, in the British Museum;[437] on an ivory of the tenth century, representing Christ in the Temple, in the Royal Library at Berlin;[438] and on the chair of the image of St. Faith, in the treasury of Conques[439] (Aveyron). The wards of ecclesiastical keys are often made to form cruciform patterns, as in the case of those of Netley Abbey, St. Serrais Maestricht, and Liège.[440] The cruciform patterns on the west face of the cross at Dysert O’Dea,[441] Co. Clare, seem to be copied from metalwork. [437] J. O. Westwood’s _Catal. of Fictile Ivories in S. K. Mus._ [438] _Ibid._ [439] _Annales de la Société Archéologique de Bruxelles_, vol. xv. (1901), p. 434. [440] Le Chanoine Rensens’ _Éléments d’Archéologie Chrétienne_, 2nd ed. (Aix, 1885), vol. i., pp. 241 and 262. [441] _Jour. R. Soc. Ant. Ireland_, ser. 5, vol. ix., p. 251. Filigree-work of gold wire is used to make the panels of interlaced-work, scrollwork, and zoömorphic designs with which some of the best specimens of Christian Celtic metalwork are decorated, such as the Ardagh Chalice, the Tara Brooch, the Hunterston Brooch, and the Clonmacnois Pin. The filigree-work is often covered with minute granulations, which add greatly to the richness of the effect produced by their texture. We have already referred to the Trichinopoly chainwork of silver wire used in the Ardagh Chalice, the Tara Brooch, and the Clonmacnois Pin. This kind of chainwork can be traced back to the Pagan Celtic period, as chains of similar character were found with the Late-Celtic gold collar at Limavady, Co. Londonderry, and with the pair of silver-gilt Kelto-Roman fibulæ from Chorley, Lancashire, now in the British Museum. Settings of coral and enamel were, as we have seen, employed for the decoration of the Late-Celtic metalwork, but in the Christian Celtic period numerous other substances were also employed, such as glass, rock crystal, amber, and other precious stones. In some cases the settings of stones and glass were rectangular with a flat top and bevelled edges, but they were more generally round, oval, or almond-shaped and “tallow-cut,” _i.e._ polished without facets.