The formation of a geode begins with the creation of an open space inside a rock. This could be an air bubble left behind inside cooling lava, or perhaps a rock that formed around an animal or plant that later decomposed away. Whatever the case, as water percolates through the rock and into the empty hole, it carries minerals with it, slowly depositing them inside. Given enough time, those microscopic mineral deposits will build into big, beautiful crystals.These prehistoric croc eggs became geodes.
[h=1]These prehistoric croc eggs became geodes![/h]