coquina

1. Any of various small marine clams of the genus Donax that are common in the coastal waters of the eastern and southern United States and have variously colored, often striped or banded shells.
2. A soft porous limestone, composed essentially of fragments of shells and coral, used as a building material.

Origin:

Origin: Spanish, cockle

Origin: , probably diminutive of concha, shell

Origin: , from Latin, mussel; see Conch