Collection: The Geodes & Clusters

Geode: A geological secondary formation within sedimentary and volcanic rocks.  Geodes are hollow, vaguely spherical rocks, in which masses of mineral matter (which may include crystals) are secluded.  The crystals are formed by the filling of vesicles in volcanic and subvolcanic rocks by minerals deposited from hydrothermal fluids.  

Cluster: A crystal cluster is a group of crystals which are formed in an open space environment and exhibit euhedral crystal form determined by their internal crystal structure.  A cluster of small crystals coating the walls of a cavity are called druse.