What are the types of rocks found on earth?

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Offline The Scientist

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What are the types of rocks found on earth?
« on: 01/07/2010 13:21:11 »
There are mainly 3 branches of rocks- Igneous, Sedimentary and Metamorphic Rocks.

But what are some examples of rocks under the three categories? Thanks!
The Scientist

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Offline Bass

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What are the types of rocks found on earth?
« Reply #1 on: 02/07/2010 07:00:57 »
Let's keep it simple...

Igneous rocks are formed from molten rock (or magma).  The rock forms when the magma cools enough for crystals to form.  Examples of igneous rocks- granite, diorite, andesite, basalt.

Sedimentary rocks are formed by the depostion and compaction of sediments (or chemical precipitation).  Most sedimentary rocks are layered.  Examples are shale, sandstone, conglomerates, limestone, etc.

In metamorphic rocks, the original minerals have been replace by new minerals- especially micas.  Metamorphic rocks are commoly layered due to the formation of micas perpendicular to the stress field.  Some common metamorphic minerals are biotite, diopside, chlorite, garnet, kyanite...  Common metamorphic rocks include shale, quartzite, marble, schist and gneiss.
« Last Edit: 05/07/2010 20:30:19 by Bass »
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Offline JimBob

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What are the types of rocks found on earth?
« Reply #2 on: 02/07/2010 17:32:10 »
See? I left one for you to answer, too, Bass!
The mind is like a parachute. It works best when open.  -- A. Einstein