Rocks and Minerals 1 Identifying rocks and

Igneous Rocks Crystallise from molten material either above (volcanic) or below (plutonic) the Earth’s surface
Characterised by interlocking crystals
Volcanic rocks fine-grained


Plutonic rocks coarse-grained


Image sources:
http://www.fs.fed.us/r2/gmug/permits/grand_valley/gv_rock.shtml
http://www.beg.utexas.edu/mainweb/publications/graphics/granite.htm<br>

Igneous Rocks Formed as a result of heat and pressure being applied to pre-existing rocks
Characterised by foliation
Structure where crystals align perpendicular to the direction of pressure
Classified by texture and mineral/chemical assemblage.


Image Source : http://www.cropsoil.uga.edu/soilsandhydrology/Important%20Rocks%20&%20Minerals.htm<br>

Sedimentary Rocks Formed when sediments are cemented together at or near the surface of the Earth
Sediments formed as a result of chemical or mechanical weathering, erosion, transportation and deposition.
Commonly form layers as sediment is deposited following erosion and transportation
May contain structures to indicate way-upness!




Image source: http://www.edupic.net/geo.htm<br>

Breccia Conglomerate Sandstone







Halite Limestone Coal Classifying Sedimentary Rock<br>

Minerals Naturally occurring substance formed through geological processes
Have a characteristic chemical composition, a highly ordered atomic structure and specific physical properties
Range in composition from pure elements and simple salts to very complex silicates with thousands of known forms
Study of minerals is called mineralogy
Can be mined and processed to obtain constituent metals

Image Source: http://en.wikipedia.org/wiki/Mineral<br>

Rocks v Minerals- What’s the difference? A mineral is made up of one substance that under normal circumstances would form crystals.
Rocks are made up of minerals.  Most rocks have several types of minerals in them, but some have only one type of mineral.  For example, sandstone is mostly quartz. 
Examples:
Minerals:  Quartz, feldspar and mica.Rocks: Granite, pegmatite, shale, slate, gneiss, schist (all made of quartz, feldspar and mica)
Mineral:  Calcite    Rock: Limestone and marble (made of calcite)
Minerals: Plagioclase feldspar and augiteRock: Basalt (oceanic volcanic rock made of plagioclase and augite)

Source: http://borntoexplore.org/ryan/rocksvs.htm<br>

Identify the samples provided as either rocks or minerals, justifying your response for each. Task<br>