Andesite
Andesite is a fine-grained, igneous, volcanic rock composed mainly of plagioclase with other minerals such as hornblende, basalt, pyroxene, pyrite, and biotite. This is the stone for grounding and focusing. Can help you to become more understanding. This stone can assist in helping us to detach from old thoughts and beliefs. Useful when you are stressed out or fighting a physical or mental disorder, can help you to heal, emotionally. 
This stone will change to a darker green over time with being worn.
 
New Zealand Stone Locally Carved in Kawerau
By Gordon Sherwood