The fifth Foundation Stone of New Jerusalem.

Sardonyx is a variety of chalcedony (fine-grained quartz) that has alternating bands of reddish-brown and white or gray. Early Roman writers spoke of sardonyx as a “gem of great value.” Sardonyx made beautiful cameos, and was often extravagantly carved. The Romans developed this craft of engraving into a fine art. Great quantities of quality sardonyx came from India during this time. Even Julius Caesar, the Roman general, became an avid collector of engraved sardonyx. The word sardonyx comes from the Greek ‘sardonux’, and has remained relatively unchanged for centuries. It is a combination of sard (the stone carnelian) and onux (‘nail of the finger’; the stone onyx) and indicates the layers of color found in the stone. It is possible that the sardonyx of Bible times was not limited to the reddish-brown and white or gray stripes. Pliny the Elder (AD 23 - 69) describes imitation sardonyx made of a triple stripe of quality white, red and black stone cemented together. Josephus, the Jewish historian, indicates this stone was used for the shoulder pieces of the ephod of the High Priest. The hebrew name is ‘yahalom’ meaning ‘to smite, or cut’. Some Greek writers considered it to mean diamond, but there is no evidence that the Hebrews knew of diamond. In contrast, onyx was a well-known stone, which was carved into seals and used with wax. Therefore, the term ‘to smite’ may mean to strike as with a seal on hot wax.

Folklore says sardonyx helps promote healthy relationships, and helps to balance heaven and earth. Used as a stone of strength and protection since ancient times, sardonyx is associated with courage, happiness and clear communication. It brings lasting happiness and stability to marriage and partnerships. Thought to increase regeneration, intuition, instincts.

One of the earliest writers to associate with the apostles the symbolism of the gems given in Revelations is by Andreas, bishop of Caesurae. He gives a brief description of the stones, which is recounted in George F. Kunz's book ‘The Curious Lore of Precious Stones’ (1913). The sardonyx represents James.