Stalactites
Water containing carbonate of lime in solution deposits a portion of it on free exposure to the air. This is often seen in calcareous caverns. The water, as it trickles from fissures in the roof, deposits its carbonate until pendent masses form there. These are called stalactites. Where the water strikes on falling, other forms similar to those above gradually grow on the floor, and are called stalagmites. When these meet and unite they form a column.