Stalactites and stalagmites are composed primarily of calcium carbonate, which is deposited from water seeping through limestone or other carbonate rocks.

Stalactites form when water seeps through the ceiling of a cave and drips onto the floor. As the water evaporates, the calcium carbonate it contains is deposited, forming a stalactite.

Stalagmites form when water seeps through the walls of a cave and drips onto the floor. As the water evaporates, the calcium carbonate it contains is deposited, forming a stalagmite.

Soda straws are not speleothems, but rather a type of mineral deposit found in caves.

Stalactites hang from the ceiling of a cave, while stalagmites grow up from the floor. Stalactites are formed by water dripping from the ceiling of a cave, while stalagmites are formed by water seeping through the walls of a cave. Stalactites are typically longer than stalagmites.

The Crystal Palace Stalactite in Jenolan Caves, Australia is the largest known stalactite in the world, measuring 7.6 meters (25 feet) long and 2.4 meters (8 feet) in diameter.

The Mammoth Stalagmite in Mammoth Cave, Kentucky, USA is the largest known stalagmite in the world, measuring 19.8 meters (65 feet) tall and 4.9 meters (16 feet) in diameter.

Stalactites and stalagmites grow very slowly, typically taking thousands of years to form.

Stalactites and stalagmites are typically white, but they can also be other colors, such as yellow, brown, or black, depending on the impurities present in the water that formed them.

Stalactites and stalagmites are made of calcium carbonate, which is deposited from water seeping through limestone or other carbonate rocks.

Stalactites hang from the ceiling of a cave, while stalagmites grow up from the floor. Stalactites are formed by water dripping from the ceiling of a cave, while stalagmites are formed by water seeping through the walls of a cave. Stalactites are typically longer than stalagmites.

The Crystal Palace Stalactite in Jenolan Caves, Australia is the largest known stalactite in the world, measuring 7.6 meters (25 feet) long and 2.4 meters (8 feet) in diameter.

The Mammoth Stalagmite in Mammoth Cave, Kentucky, USA is the largest known stalagmite in the world, measuring 19.8 meters (65 feet) tall and 4.9 meters (16 feet) in diameter.

Stalactites and stalagmites grow very slowly, typically taking thousands of years to form.

Stalactites and stalagmites are typically white, but they can also be other colors, such as yellow, brown, or black, depending on the impurities present in the water that formed them.