Amethyst has great history; it is mentioned in the Old Testament as one of the twelve stones representing the twelve tribes of Israel. It was also one of the twelve gemstones adorning the breastplate of the high priest Aaron. With its association with religion, Amethyst has been set into rings and worn by Cardinals, Bishops and Priests of the Catholic Church since the Middle Ages. Over the years, the gem has also been cherished by royalty and several pieces can be found in the British Crown Jewels. Amethyst was also set in the so-called Papal Ring (Italian, 15th century) in the Jewellery Museum in Pforzheim.