Definitions I
igneous rock are rocks that are fromed directly from magma or lava. They are classfied as either intrusive or extrusive according to the conditions of their formation, interior or exterior to the earth's surface.  

intrusive Igneous rock that cools and hardens deep below the surface of the earth. Intrusive rocks are identified by their course texture (large crystals) the crystals within intrusive rocks usually have a long period of time to form, therefore they are able to build larger crystal sturctures.

  

 

Definitions L

layers refers to the sequence in which sediments were deposited and made into rock

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This rock shows obvious layers, which are a result of the different times that sediments were deposited, then glued together to make this rock.

Limestone

A chemical sedimentary rock which forms mainly form the precipation and reaction of lime (CaCO3) in Ocean water. Limeston often has many fossils of organisms within its structure.
   
Definitions M

metamorphic rock

  
Mineral  
   
Definitions N
nonsilicates