A stalactite is a a type of speleothem which hangs from the ceiling or wall of a limestone cave. It is formed from the deposit of calcium carbonate and the dripping of mineralized solutions. The corresponding formation on the floor underneath a stalactite is known as a stalagmite. Should both these formations grow together, meeting in the middle, the resultant formation is known as a column or pillar. The term "stalactite" is derived from the Greek meaning to fall in drops; "stalagmite," from the Greek meaning that which drops.

To remember which formation hangs from the ceiling (stalactite) and which grows upward from the floor (stalagmite) think of:

  • Stalactites hang "tite" to the ceiling above
  • Stalagmites you "mite" trip over if you don't watch where you're stepping

See also