SAND'STONE, n. [sand and stone.] Sandstone is, in most cases, composed chiefly of grains of quartz united by a cement, calcarious, marly, argillaceous, or even silicious. The texture of some kinds is loose, of others close; the fracture is granular or earthy.

Sandstones usually consist of the materials of older rocks, as granite, broken up and comminuted, and afterwards deposited again.