Igneous Rocks
Formation
Igneous rocks are formed from magma or lava
Magma – melted rock inside the earth
Lava – melted rock outside the earth
Types and Traits
There are 2 types of igneous rocks, intrusive and extrusive
Intrusive – formed inside the earth from magma. Has crystals in it.
Extrusive – formed outside the earth from lava. It can be glassy or porous (holey)
Igneous rocks are formed from magma or lava
Magma – melted rock inside the earth
Lava – melted rock outside the earth
Types and Traits
There are 2 types of igneous rocks, intrusive and extrusive
Intrusive – formed inside the earth from magma. Has crystals in it.
Extrusive – formed outside the earth from lava. It can be glassy or porous (holey)
Below is a table of different types of rocks that are made of the same material but are different just because they were formed inside or outside the earth.
Crystal Size
Crystal Size in intrusive rocks depends on how long it takes to cool. If a rock takes a long time to cool, the crystals will be large. If a rock takes a short time to cool, the crystals will be small.