Rocks and rock cycle

A rock is a NATURALLY OCCURRING, COHERENT (i. e A rock is a NATURALLY OCCURRING, COHERENT (i.e. not a pile of loose materials) SOLID material, consisting of: ONE OR MORE MINERALS, or, GLASS (e.g. obsidian), or, ORGANIC MATTER (e.g. coal)

Metamorphic rocks Sedimentary rocks Erodes Becomes That weathers Deposits and lithifies, Exposed to: Increased pressure High heat Hot fluid Any existing rock Becomes Photos by Prajukti Bhattacharyya Mississippi Delta image courtesy Liam Gumley, Space Science and Engineering Center, University of Wisconsin-Madison and the MODIS science team (source: http://earthobservatory.nasa.gov/IOTD/view.php?id=1257, accessed August 20, 2014) is freely available for re-use under these terms: http://www.nasa.gov/audience/formedia/features/MP_Photo_Guidelines.html#.U6MgBxbntvU That melts Which cools to make Sedimentary rocks Becomes magma Igneous rocks

Igneous rocks Form when magma becomes solid Form either by cementing broken pieces of pre-existing rocks together (e.g. sandstone), or, by precipitation of minerals out of water solution (e.g. limestone) Sedimentary rocks Form when pre-existing rocks are altered by heat and/or pressure and/or hot fluids into new rocks without becoming anything else in between. Metamorphic rocks