A stalagmite is a type of mineral formation that grows upward from the floor of a cave. It forms when mineral-rich water drips from the ceiling, leaving behind deposits of minerals like calcium carbonate as it evaporates. Over time, these deposits accumulate, creating a column-like structure. Stalagmites are often found in conjunction with stalactites, which hang from the ceiling of caves. Both formations are part of a larger group known as speleothems, which are cave formations created by the deposition of minerals. Stalagmites can vary in size and shape, depending on the rate of mineral deposition and the cave's environmental conditions.