Stalactites and stalagmites are rock formations that occur inside limestone caves. A stalactite forms itself from the ceiling of the cave while a stalagmite forms itself from the floor of the cave. This old saying will help you remember the difference between stalactites and stalagmites. "A stalactite holds tight while a stalagmite stands upright.".

             Stalactites are formed from rainwater. Rainwater is very acidic even without the pollution in the air. When it rains, tiny raindrops are formed. The raindrops dissolve carbon dioxide gases in the air and form a weak carbonic acid. The raindrops then seep into the ground. The groundwater eats away at the calcite in the earth. Calcite is the main mineral in limestone rock. The acid dissolves the limestone and makes designs in the rock. Flowing acidy water can carve a cavern underground. The underground water moves the dissolved calcite and deposits in a different place. .

             When the water seeps into the ground it may hang on the ceiling of the cave as a droplet. This droplet is known as a minute mineral particle. As the droplet evaporates, it deposits the calcite on the ceiling or the floor of the cave. The next droplet that seeps in will create a build up of the calcite. This build up is what forms the stalactite or stalagmite. In many caves throughout southern Indiana there are many examples of stalactites and stalagmites.

             Since stalactites and stalagmites are formed the same way, many people tend to see them as only icicle shaped rocks in a cave. There are many differences between them. Most of these differences result in how they form. .

             There are three basic types of stalactites and it can take up to a thousand years to form just a centimeter of stalactite. It just depends on how fast the droplets of water seep .

             through the earth. Some stalactites are long and thin and some are very large. Water forming droplets on the ceiling or on the walls of the cave form a build up of calcite.