Sedimentary structures formed of calcium carbonate, stalactites are sometimes colored by impurities, such as iron oxide.

TEXTURE These crystalline structures occur in the shape of pendants grown from the roofs of caves, especially in limestone regions. While stalactites are long, slender forms, the corresponding structures— stalagmites—that grow up from the cave floor are stumpy and shorter. The two sometimes join together to form calcite columns.

ORIGIN These structures form by inorganic precipitation of calcium carbonate from waters seeping through fractures in the roofs of caves.
When lime-rich waters meet the air and carbon dioxide is released, calcium carbonate is deposited, while evaporation of the water speeds up the process.
Lime-rich water, dropping from the end of a stalactite, results in the formation of a stalagmite.

Grain size: Fine to medium

Classification: Chemical

Fossils: None

Grain shape: Angular