Shale

Shale is a fine-grained form of rock.

Some hills on Capella IV were composed of shale. In 2267 James T. Kirk and Spock used their communicators to create a sonic disruption which toppled a rock face comprised of shale. The rocks collapsed, blocking the entrance to a canyon and making it more difficult for Kras and a group of Capellans to reach Kirk and his party. 

In 2371, Neelix talked with Jetrel about the Talaxians on Rinax who survived the metreon cascade. He described the flesh of the survivors as "horribly charred, the color of shale."

Shale was also used as slang term for a lie or perceived falsehood. The word was often used by the Human descendants of the Terra Nova colony.