Stalactite and stalagmite are speleothems, which are minerals that form into structures that line the insides of caves. Stalactites hang from the ceiling of the cave, like icicles, and stalagmites grow upwards from the ground like a cone. Sometimes, the two meet in the middle.


The word stalactite comes from the Greek word stalasso, meaning “to drip” or “that which drips.” It was first used by Ole Worm, a Danish physician, in the 17th century.
The word stalagmite comes from the Greek word stalagmites, which means “dropping, trickling.”
Both words can be traced to the Greek word stalassein, which means “to drip.”

Scientific composition of stalactite and stalagmite

Stalactite and stalagmite are speleothems, which are deposits of minerals typically found lining caves. They vary in growth – some take thousands of years to form, while others form more quickly. Together, the two are commonly referred to as “dripstone.” Both of these dripstones are formed from the deposition of calcium carbonate. When combined with water and carbon dioxide, calcium bicarbonate is made; when the calcium bicarbonate hits the surface (rock, or otherwise), it makes a deposit of calcium carbonate. Over time, this deposit builds up into stalactite and stalagmite. The fastest growing stalactite grows about .12 inches per year, making this a long, drawn out growth process.

Stalactite and stalagmite can also form on concrete and in lava tubes; however, when it forms in lava tubes, the process is different. In order for stalactite to form, limestone or other minerals must be present in the water.

Where can I find stalactite and stalagmite?

There are several locations that claim to house the “longest stalactite in the world.” For example, the White Chamber in Jeita Grotto’s upper cavern in Lebanon has a 27 foot stalactite, which people come to visit. An even longer stalactite lives in the Chamber of Rarities in the Gruta Rei do Mato, in Brazil. The largest stalagmite is 204 feet high and resides in Cueva Martin Infierno, Cuba.

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