Internal Igneous rock is an Igneous rock that has been created by the magma cooling inside the volcano. They have bigger
crystals because the magma cooled down more slowly. Examples of Internal Igneous rocks are granite and diorite.
External
External Igneous rock is an Igneous rock that has been created by the magma cooling on the outside of the volcano. Magma is outside the volcano it is
known as lava. External Igneous rocks have smaller crystals because the lava cooled down more quickly because of the exposure to air. Examples of
External Igneous rocks are obsidian and basalt
Sedimentary
How they are formed
Weathering
Weathering is the process in which the weather destroys a piece of rock and the
grains and dust of the destroyed rock fall down into a river. Lightning, change in
temperature, ice and rain are a few of the ways weathering occurs.
Transporatation
Transportation is the movement of the remaining rubble of the destroyed rock. A river is the most common
way that the rubble is moved
Deposition
Deposition is the depositing of rubble from a fast transportation method, like a river, to a slow moving source, like the sea.
Because of the change of speed, the rubble is now dropped instead of carried which starts the formation of the sedimentary rock.
Burial
Burial is the burying of the deposited rubble. This occurs when more rubble is deposited on the
newer rubble which buries the original rubble
Compaction
Compaction is the connection of the rubble that has been buried. The force and weight of the large pile of rubble forces the
rubble to completely crumble to create a massive dust rubble pile.
Cementation
Cementation is the solidification of the dust rubble pile. The water causes the dust to stick
together and eventually the sticky dust stick to each other and become one solid sedimentary
rock.
Metamorphic
How they are formed
Heat
Metamorphic rock is sedimentary rock that has been changed due to heat
Pressure
Metamorphic rock is sedimentary rock that has been changed due to pressure
Properties
Igneous
Igneous rock has interlocking grains, crystals and is non porous
Sedimentary
Sedimentary rock has fossils and layers
Metamorphic
Metamorphic rock has interlocking grains, crystals, and is non porous. Some
metamorphic rocks have fossils in them.