Pointed rock formations that are formed on the ceilings of caves by the mineral deposits of dripping water are called…

A Stalagmites
B Rockcicles
C Stalactites

Stalactites descend from the ceiling, whereas stalagmites are formed underneath them on the ground by the same process. An easy way to remember them is stalactites have a ‘C’ for ceiling, and stalagmites have a ‘G’ for ground.

The correct answer is Stalactites.