Different+types+of+rocks


 * Basalt** is an igneous rock. It is the most common rock is the world. It forms from the melting of the upper mantle. Basalt originates from volcanoes. it has alot of magnesium in it.




 * Sandstone** is a common sedimentary rock. It is formed in many environments. it is found just about anywhere there is water, if it is frozen or not, in a river or an ocean. Even if there is no water as in a desert, there is probobly sandstone underground. Sandstone has formed in layers.




 * Tuff** is made out of consolidated volcanic ash from vents during a volcanic eruption. Tuff is sometimes called tufa, particularly when used as construction material. It is an igneous rock




 * Marble** is a metamorphic rock made out of limestone. When limestone is subjected to tremendous pressure for a long time like if limestone is buried under a lot of other rock or an ocean it gets squashed into marble. Marble is more beautiful than limestone and tougher, and so people like to use it for buildings.


 * Obsidian** is a igneous rocks that formed when lava cools quickly above the ground. Obsidian is actually glass and not a mixture of minerals.

Bath Stone has been used extensively as a building material throughout the world, for churches, houses and public buildings such as railway stations. it is a sedimentary rock.
 * Bath Stone** is a type Limestone. Bath Stone is a freestone which means it can be cut into any shape.

Portland Stone is formed on the floor of the ocean close to land. it is a sedimentary rock.
 * Portland stone** is a type of limestone. It has been used as a building material throughout the world.

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