What is the Earth made up of?
The whole earth is made of rocks & minerals. Within the earth there is a liquid core of molten rock and on the outside there is a hard crust.The crust is made up of rocks and minerals
Below the loose layer of soil, sand & crumbled rocks found on surface of the earth is bedrock, which is a solid rock.

• The Crust comprises of 1% of the Earth's mass (0.4%) It consists of oxygen, magnesium aluminum, silicon calcium, sodium potassium, iron.
  
  
• The Mantle is the beneath the crust and is about 2900 km thick. It makes up about 70% of the Earth's mass (68.1%). Largely made up of silicon, oxygen, aluminum and iron.
  
  
• The Core is the inner most layer of the ore an is mainly made of iron and nickel and makes up about 30% of the Earth's mass (31.5%).It is further divided into the inner and outer core. The Outer Core is 2200 km thick and is liquid and the Inner core is 1270 km thick and is solid.

Rocks are often classified by how they were formed. Rocks are classified into three main groups: igneous, sedimentary, and metamorphic.

Igneous Rocks

Igneous means made from fire or heat. Igneous rocks are made from hot, molten rock material that has cooled and hardened. Molten rock that is below Earth's surface is called magma. When magma reaches the surface of earth is called lava.
When a volcanoe eruption occurs the liquid rock comes up to the earth's surfacemaking new igneous rock.When it cools & turns hard it is called obsidian, lava rock or pumice - depending on what it looks like. As molten rock cools slowly it forms large crystals conversly molten rock that cools quickly makes small crystals.
If magma hardens inside the crust, it turns into granite. Which is very hard since it cools very slowly.

There are 5 kinds of igneous rocks,which vary depending on the mix of minerals in the rocks.

Sedimentary rocks

Sediments are laid down in time order. Those at the bottom are laid down first, while those at the top are laid down last. Time order tells us about age.

Sedimentary rocks are formed from bits or layers (strata) of small rocks. Deposited rock particles, called sediments, settle in layers. The weight of the layers packs the particles together into rock. Some sedimentary rocks are made of once-living things. Limestone is made of the shells and skeletons of once-living sea animals.

Sedimentary rocks have fossils in them because plants & animals that have died get covered up by new layers of sediment and are turned into stone. Most of the fossils we find are of plants & animals that lived in the sea. They just settled to the bottom. Other plants & animals died in swamps, marshes or at the edge of lakes and were covered with sediments when the size of the lake got bigger.
When large amounts of plants are deposited in sedimentary rocks, then they turn into carbon, which gives us our coal, oil, natural gas and petroleum.

There are 6 main kinds of sedimentary rocks depending on the appearance of the rock.

Those sedimentary rocks that formed through the chemical precipitation of inorganic materials ("chemical" rocks) include halite (rock salt), gypsum and anhydrite (calcium sulphate minerals), iron-rich sedimentary rocks as limonite and hematite, and some limestones, dolostones, and cherts. Sandstone, shale, and limestone comprise the most abundant sedimentary rocks in New York State.

The term metamorphism means to change. Rocks will alter their form and appearance to suit new conditions Metamorphism is a slow process that occurs deep within the Earth and cannot be directly observed but we can see the end result, metamorphic rocks.

Metamorphic rocks are the least common of the 3 kinds of rocks. .Metamorphic rocks are rocks that have changed.A metamorphic rock is a rock that has been changed by heat and pressure. The heat that causes the change may come from nearby magma, and the pressure comes from the weight of other rocks stacked on top.

The word comes from the Greek "meta" and "morph" which means to change form. Metamorphic rocks are igneous or sedimentary rocks that have been transformed by great heat or pressure and due to movement of the earth's crust.

Rocks are always changing. The rock cycle is a process by which rocks are changed from one type to another. Magma or lava cools and forms igneous rocks. Rocks on Earth's surface break into small pieces. In time, the small pieces turn into sedimentary rocks. Temperature and pressure may also change rocks. Rocks below Earth's surface may melt and form magma, and the cycle repeats.For example, marble is a metamorphic rock that once was limestone.

As the earth's crust moves, it causes rocks to get squeezed so hard that the heat causes the rock to change. Marble is an example of a sedimentary rock that has been changed into a metamorphic rock.

Uses of Metamorphic Rocks

Slate is used to make roofing tiles and in earlier periods of our history was used as "blackboards" in classrooms. As a resource, slate is nonrenewable, but common. Man-made roofing tiles are a suitable substitute.

Marble is used as a building stone and as ornamental rock, such as for carving statues. As a resource, marble is nonrenewable, but common. Man-made building stones are a suitable substitute.