1. Mineral deposits that form in a cave after the creation of the cave itself.
2. A secondary mineral deposited in a cave by the action of water; cave formation.

These deposits are generally composed of calcium carbonate dissolved from the surrounding limestone by groundwater. Carbon dioxide carried in the water is released as the water encounters the cave air; this reduces the water's capacity to hold calcite in solution and causes the calcite to be deposited.

Such deposits may accumulate to form stalactites, stalagmites, flowstone, cave pearls, and many other formations.

Speleothem growth can be dated by the uranium series dating method and they can potentially bury earlier archaeological deposits.