Sardonyx is a stone with many spiritual meanings, including:
Strength and protection
Sardonyx has been used as a stone of strength and protection since ancient times.
Courage, happiness, and clear communication
Sardonyx is associated with these qualities.
Stability in relationships
Sardonyx is said to bring lasting happiness and stability to marriages and partnerships.
Charisma
Some say that sardonyx can give the wearer such an incredible charisma that it should be used with care.
Protection from evil
Some believe that placing sardonyx at each corner of a house will protect against evil.
Heightening traits
Black and white-banded sardonyx is said to heighten traits such as cleverness, versatility, and optimism.
Controlling traits
Black and white-banded sardonyx can also be used to help control traits that are working against the wearer. 
 
Sardonyx is found in many regions around the world, including Brazil, India, Germany, Uruguay, Russia, and the Lake Superior region of the United States. The most sought-after sardonyx comes from India, where the geological composition produces vibrant, flawless, and colorful stones.