Sardonyx

 
 

Sardonyx is an onyx that is characterized by parallel lines of sard and different colored minerals. It is a distinct and dramatically banded variety of chalcedony composed of quartz layers. Typically found in black, brown and white layers. Metaphysically, Sardonyx is believed to improve memory and increase one's analytical talents. Mined all over the globe. The best stone is said to come from India.