It expels negative thoughts from the conscious. Star Sapphires are best worn as a ring, and they are best for work with the Chakras. They focus energies. Star Sapphires are best when set in pure silver. Sard is thought to be what is now called Carnelian.
Sard offers protection against incantations and sorcery, and they sharpen the wit.
Sardonyx is a variety of chalcedony Quartz with colored bands. It is also a variety of Onyx generally of a reddish-yellow, consisting of Sard and white chalcedony in alternate layers. Sardonyx gives conjugal felicity. It favors fortune. The woman whose stone it is and who neglects to wear it is doomed to a lonely existence.