Blonde Girl Posing At The Tree In The Backyard Of The Old Stone House On The Sea Coast

In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.
The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic. The scientific study of rocks is called petrology, and petrology is an essential component of geology.