(n.) Any crystalline rock having a foliated structure (see Foliation) and hence admitting of ready division into slabs or slates. The common kinds are mica schist, and hornblendic schist, consisting chiefly of quartz with mica or hornblende and often feldspar.

aa abyssal rock basalt bedrock block lava brash breccia conglomerate crag druid stone festooned pahoehoe gneiss granite igneous rock lava limestone living rock magma mantlerock metamorphic rock monolith pahoehoe pillow lava porphyry pudding stone regolith rock ropy lava rubble rubblestone sandstone sarsen scoria scree sedimentary rock shelly pahoehoe stone talus tufa tuff