a. An ancient term for ironstone, North Staffordshire, U.K.
b. A large crystalline mass of limestone containing coral in position of
growth, surrounded by shale and impure bedded limestone.
See also: caballa ball
c. A nodule or large rounded lump of rock in a stratified unit; specif. an
ironstone nodule in a coal measure. Syn: ball
Dictionary of Mining, Mineral, and Related Terms