July 12, 2001
The creation of the calcite structures commonly found in many limestone caves is a very long and slow natural process. Water containing dissolved calcium carbonate slowly flows into the room through cracks in the ceiling. When the water drips off or evaporates, it leaves behind a very tiny layer of solid calcium carbonate (calcite), which builds up over centuries to create the structures. In this photo, many stalactites and "soda straws" can be seen hanging from the ceiling in the California Cavern. The soda straws are hollow, allowing the water to pass through the center, until it drips off the bottom and adds to the length of the formation. Sometimes a soda straw gets plugged at the end, at which time the calcite begins to grow on the outside, transforming it into a more "traditional" stalactite.