NSES Content Standard D 
Earth and Space Science: Structure of the Earth system
Grades 5-8, page 160

Some changes in the solid earth can be described as the "rock cycle." Old rocks at the earth's surface weather, forming sediments that are buried, then compacted, heated, and often recrystallized into new rock. Eventually, these new rocks may be brought to the surface by the forces that drive plate motions, and the rock cycle continues.
 

 
Benchmark 4C The Physical Setting: Processes that Shape the Earth
Grades 6-8, page 73
Sediments of sand and smaller particles (sometimes containing the remains of organisms) are gradually buried and are cemented together by dissolved minerals to form solid rock again.

Benchmark 4C The Physical Setting: Processes that Shape the Earth
Grades 6-8, page 73
Sedimentary rock buried deep enough may be reformed by pressure and heat, perhaps melting and recrystallizing into different kinds of rock. These re-formed rock layers may be forced up again to become land surface and even mountains. Subsequently, this new rock too will erode. Rock bears evidence of the minerals, temperatures, and forces that created it.

Benchmark 4C The Physical Setting: Processes that Shape the Earth
Grades 9-12, page 74
The formation, weathering, sedimentation, and reformation of rock constitute a continuing "rock cycle" in which the total amount of material stays the same as its forms change.