Web Results

en.wikipedia.org/wiki/List_of_rock_types

The following is a list of rock types recognized by geologists.There is no agreed number of specific types of rocks. Any unique combination of chemical composition, mineralogy, grain size, texture, or other distinguishing characteristics can describe rock types.

geology.com/rocks

Rocks: Igneous, Metamorphic and Sedimentary Rocks hold the history of the earth and the materials that will be used to build its future. Igneous. Igneous Rocks: Photos, descriptions and facts about intrusive and extrusive igneous rocks. Andesite. Basalt. Dacite. Diorite. Gabbro. Granite. Obsidian. Pegmatite. Peridotite. Pumice. Rhyolite.

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

Types of Rocks Rocks are not all the same! The three main types, or classes, of rock are sedimentary, metamorphic, and igneous and the differences among them have to do with how they are formed. Sedimentary Sedimentary rocks are formed from particles of sand, shells, pebbles, and other fragments of material.

jersey.uoregon.edu/~mstrick/AskGeoMan/geoQuerry13.html

Sedimentary rocks are called secondary, because they are often the result of the accumulation of small pieces broken off of pre-existing rocks. There are three main types of sedimentary rocks: Clastic: your basic sedimentary rock. Clastic sedimentary rocks are accumulations of clasts: little pieces of broken up rock which have piled up and been ...

en.wikipedia.org/wiki/Rock_(geology)

Metamorphic rocks are formed by subjecting any rock type—sedimentary rock, igneous rock or another older metamorphic rock—to different temperature and pressure conditions than those in which the original rock was formed. This process is called metamorphism, meaning to "change in form".The result is a profound change in physical properties and chemistry of the stone.

www.wisegeek.com/what-are-the-different-types-of-rocks.htm

Metamorphic rocks are formed when a preexisting rock, called a protolith, is under conditions of high heat and pressure, causing it to metamorphose chemically, structurally, or both. The protolith might be an igneous, sedimentary, or another metamorphic rock.

www.zmescience.com/other/science-abc/types-of-rock

The three types of rocks. It’s the first thing you learn in a geology class — very briefly the three types of rocks are:. Igneous — they form from the cooling of magma deep inside the earth ...

geology.com/rocks/igneous-rocks.shtml

Igneous rocks are formed from the solidification of molten rock material. There are two basic types. Intrusive igneous rocks crystallize below Earth's surface, and the slow cooling that occurs there allows large crystals to form.

www.eartheclipse.com/geology/basic-types-of-rocks.html

Igneous rocks are of two types, intrusive and extrusive. Intrusive igneous rocks are formed when the magma cools off slowly under the earth’s crust and hardens into rocks. Gabbro and granite are examples of intrusive igneous rocks.