Cave Formations Cave formations are deposits on the ceiling, floor, and walls of a cave. They are called speleothems. Most caves have enough openings to allow air movement, which does evaporate some of the moisture and causes the precipitation of calcite and aragonite from the seeping waters.
Nature creates formations in a cave very slowly.
It may take one hundred to one hundred fifty years to form an inch of material to the speleothems. These speleothems may take the form of icicles, trees, statues, or the delicate design of lacy flowers. The coloration of these structures varies from white or cream, to yellowish or dark brown which is due to the presence of limonite that is dissolved from the overlaying rocks. The red and orange hue comes from dissolved iron mixing with water to form iron oxide. The blue is derived from manganese.