Various articles of jewelry associated by use and decoration with the Christian religion, although some also had decoration of a secular nature or were used for reasons of superstitions or supposed magical powers.
The earliest types were the signet rings decorated with various Christian symbols or inscriptions, usually made of iron or bronze but sometimes of gold. Another early example was the reliquary in the form of a pendant or a finger ring; these were worn especially in the 13th to 15th centuries.
Other types of devotional jewelry of the period were the devotional ring, and Agnus Dei pendant, end the pendants decorated with relief figures of saints.
From: An Illustrated Dictionary of Jewelry, autor: Harold Newman, publishers: Thames and Hudson