Petrified wood.
 
Grounding – Security - Soothing 
 
Petrified Wood is a stone of transformation. It assists to advance to ones highest chosen level. Helps to make one feel safe and secure, calming down survival based fears.
It has the ability to soothe emotions, generate calm, and dispel stress. When a Petrified Wood is near, all your fears will simply disappear. Petrified Wood is a very healing and grounding stone that fills you with feelings of security. 
 
Chakra: Root.