Stalagmites are formations formed from the cave floor upward in a mound-shaped mineral deposit. They are comprised of mineral deposits formed by water interacting with bedrock. Stalagmites are usually of calcite mineral-bearing solutions dripping from the ceiling, and often form under stalactites. If the two grow together, they form a column.

are conical deposits of calcium carbonate on the floors of limestone caverns, formed by crystallisation from groundwater.