Collection: Geodes

Geodes are formed when hollow cavities within rocks, often in igneous or sedimentary rocks, fill with minerals deposits, creating unique, crystal-lined interiors. These cavities can form from gas bubbles in cooling lava, dissolved fossils or organic matter in sedimentary rocks, or even from the dissolution of nodules. Mineral-rich ground water then seep into these cavities, and as water evaporates or chemical changes occur, the dissolved mineral precipitate out and crystallize on the cavity walls.