A quarry is where a fine-grained, foliated, homogeneous metamorphic rock has been excavated.
A quarry is a place from which dimension stone , rock , construction aggregate , riprap , sand , gravel , or slate has been excavated from the ground . Slate is a fine-grained , foliated , homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism .