4th and 7th chakra crown.  This lovely stone is also called chalcedony, but Grape Agate sounds so much better, and the little spheres of chalcedony do resemble grapes. When holding the grape agate I feel peaceful;  a zen-like tranquility enters my crown chakra at an amazing rate,  then I feel myself slipping into that well known void.  With the added green color this crystal will allow you to fill your heart of love and compassion!  Great combo!
 
Physically I have found this stone to lesson the pain of 'stress' headaches and to relax stiff muscles. Promotes restful sleep while relieving depression. Aids in relaxing a nervous stomach. To use Grape Agate as an aid for an upset stomach, simply pass this stone over the solar plexus stomach area. Visualize the healing energy of this stone working to melt away or remove this pain.
Gemological Properties- Grape Agate is a cryptocrystalline quartz. Quartz is a group of mineral species which is from the hexagonal (trigonal) crystal system. The chemical composition is SIO2, refractive index is 1.544-1.553 with a specific gravity of 2.66. From Indonesia.