1. Formation of the Geode Cavity: A geode starts as a hollow space within a rock. This space can form in various ways, like gas bubbles in volcanic rock, or when water dissolves minerals leaving a cavity.
2. Mineral-Rich Water: Water carrying dissolved minerals seeps into the cavity.
3. Crystallization: As the water inside the geode evaporates, the dissolved minerals start to crystallize. They arrange themselves in an orderly pattern, forming the beautiful crystals we see.
4. Growth: Over time, the crystals continue to grow, filling the geode cavity with their intricate structures.
So, the crystals inside the geode are formed within the existing geode cavity during a later stage of its geological history.
