Processional crux gemmata (jewelled cross) from the treasury of the Cathedral of the Virgin Mary in Aachen, made before the year 1000. Core of oak wood covered with silver sheet, almost entirely gilded, set on a 14th-century base probably made of a chalice. Reverse, so-called August or imperial side, covered with filigree and richly decorated with 102 precious stones, above all emeralds, rubies and amethysts and 35 pearls. In the center of the cross there is a cameo of sardonyx depicting the Roman Emperor Octavian Augustus. The smooth obverse is decorated with engraved figural representations, first of all the Crucified Christ.