What is a rock?
A rock is a solid.
A rock occurs naturally.
A few rocks are made up of just one mineral.
Most rocks are a solid mixture of several minerals.
There are just three different types of rocks: igneous, sedimentary, and metamorphic.
Petrology is the study of rocks.

kidcyber recommends the following sites for information about rocks

Go here to view animations that will show you how the three different kinds of rocks are formed.http://www.fi.edu/fellows/fellow1/oct98/create/index.html

An animated page from the BBC is here
http://www.open2.net/sciencetechnologynature/worldaroundus/geologytooklit/rocktypes_embedded.html

What rocks are and the three kinds of rocks are here
http://geomaps.wr.usgs.gov/parks/rxmin/rock.html

http://www.learner.org/interactives/rockcycle/types.html

Another animation of how rocks are formed
http://www.childrensmuseum.org/geomysteries/faqs.html

Sing a song to help you remember the three different kinds of rocks
http://www.chariho.k12.ri.us/curriculum/MISmart/ocean/rocksong.htm

A-Z lists of the names of the three types of rocks with information and a photograph about each
Igneous rocks ahttp://csmres.jmu.edu/geollab/Fichter/IgnRx/IgAlphabetical.html
Sedimentary rocks http://csmres.jmu.edu/geollab/Fichter/SedRx/Sedalphab.html
Metamorphic http://csmres.jmu.edu/geollab/Fichter/MetaRx/Metaalphab.html

For photographs (and information) of many different kinds of rocks go to http://www.rocksandminerals4u.com/igneous_metamorphic_sedimentary_rock.html

The rock cycle
The three rock types are related to each other, and the Earth processes changes to rocks from one type to another. The rock cycle is an ongoing process over millions of years. Igneous rock can change into sedimentary rock or into metamorphic rock. Sedimentary rock can change into metamorphic rock or into igneous rock. Metamorphic rock can change into igneous or sedimentary rock.

Read about the rock cycle here

http://www.oum.ox.ac.uk/thezone/rocks/cycle/index.htm

http://www.cotf.edu/ete/modules/msese/earthsysflr/rock.html

Back to Planet Earth

updated September 2008