Rough piece of Green Onyx.
 
Onyx is strength giving. It provides support in difficult or confusing circumstances and during times of enormous mental or physical stress. Centering your energy and aligning it with a higher power, accessing higher guidance. Facilitates being master of ones destiny. 
It aids in learning lessons, imparting self confidence and helping you to be at ease in your surroundings. 
 
For healing  - Onyx is beneficial for teeth, bones, bone marrow, blood disorders and feet. Treats addictions.