Black onyx is thought by some to have protective qualities, making it advantageous to carry when one is traveling. From Brazil.

Onyx eliminates negative thinking, it is also believed to sharpen the wits of the wearer. Onyx is said to bring spiritual inspiration. It is a great assistance in holding emotions and passions under control. Black Onyx is used to help one change habits.

This stone is fairly hard so you can use a steamer and ultrasonic cleaner with it.