Coconut Geode Properties Coconut Geode can be hollow, semi-hollow, or filled with quartz and agate. They generally range from 2 to 6 inches in diameter and are a sure definition of mesmerization. They are a fantastic work of mother earth’s art that fascinates and lures jewelry lovers worldwide. Different minerals inside the hollow crust of geodes bling like the stars on a dark night, adding to the attractive features of these natural creations.