<P> A stalactite (UK: / ˈstæləktaɪt /, US: / stəˈlæktaɪt /; from the Greek stalasso, (σταλάσσω), "to drip", and meaning "that which drips") is a type of formation that hangs from the ceiling of caves, hot springs, or manmade structures such as bridges and mines . Any material which is soluble, can be deposited as a colloid, or is in suspension, or is capable of being melted, may form a stalactite . Stalactites may be composed of lava, minerals, mud, peat, pitch, sand, sinter, and amberat (crystallized urine of pack rats). A stalactite is not necessarily a speleothem, though speleothems are the most common form of stalactite because of the abundance of limestone caves . </P> <P> The corresponding formation on the floor of the cave is known as a stalagmite . </P>

What are natural structures hanging from a cave ceiling