Imagine a cave...
What comes to mind?
You probably thought of those sharp horizontal shapes, some pointing down and some pointing up, right?
These formations are called stalactites, when they are at the top; and stalagmites, when they are down. Both are formations resulting from water dripping from cracks in limestone cave walls, carrying part of the limestone. Upon contact with air, it precipitates a ring of calcite at the base of this drop. This process is repeated as long as there is water penetrating through the crack: each new drop will give rise to a new ring of calcite, consolidating conical and pointed shapes called stalactites.
Stalactite and stalagmite tend to come together, as the latter is the result of the drip that gave rise to that one - the drops of the stalactites, when they fall to the bottom of the cave, they tend to precipitate, giving rise to stalagmites, which have a coarser shape: more rounded, less pointed. From this union, we have a new speleothem: column.
The growth process of these speleothems (mineral formations that occur in caves) is long and continuous - it varies between 0.01mm to 3mm per year and depend on factors such as amount of water, drip speed, limestone purity and temperature. Sometimes, stalactites follow crevices in the ceiling, and can reach much larger dimensions.
Speaking of “majors”, the largest stalactite recorded in Brazil is located in Gruta do Janelão, in Januária – MG. "Ballerina's leg" - as it is called, it is 28 meters long:
By Mariana Araguaia
Brazil School Team
Source: Brazil School - https://brasilescola.uol.com.br/curiosidades/estalactites-estalagmites.htm
