Rocks There are three main types of rocks: 1. Igneous 2. Sedimentary 3. Metamorphic

Igneous rocks Igneous rocks are called fire rocks Igneous rocks are called fire rocks formed either underground or above ground formed either underground or above ground Underground, they are formed when the melted rock, magma, becomes trapped in small pockets. Underground, they are formed when the melted rock, magma, becomes trapped in small pockets. Igneous rocks are also formed when volcanoes erupt. Igneous rocks are also formed when volcanoes erupt.

Igneous Rocks Granite formed by slowly cooling pockets of magma that were trapped beneath the earth's surface formed by slowly cooling pockets of magma that were trapped beneath the earth's surface used for long lasting monuments and for trim and decoration on buildings used for long lasting monuments and for trim and decoration on buildings

Pumice formed when lava cooled quickly above ground. formed when lava cooled quickly above ground. You can see where little pockets of air had been. You can see where little pockets of air had been. This rock is so light, that many pumice rocks will actually float in water. This rock is so light, that many pumice rocks will actually float in water.

Obsidian form when lava cools quickly above ground form when lava cools quickly above ground

Igneous rocks pa.edu/earthsci/imag earchive/igenous.htm pa.edu/earthsci/imag earchive/igenous.htm pa.edu/earthsci/imag earchive/igenous.htm pa.edu/earthsci/imag earchive/igenous.htm Igneous Rocks : Formed from the cooling of molten rock. Igneous Rocks : Formed from the cooling of molten rock.

Sedimentary Small parts or sediments of rock are weathered and settle to the bottom of the rivers, lakes, and oceans. Small parts or sediments of rock are weathered and settle to the bottom of the rivers, lakes, and oceans. Layer after layer of eroded earth is deposited on top of each. Layer after layer of eroded earth is deposited on top of each. These layers are pressed down more and more through time, until the bottom layers slowly turn into rock. These layers are pressed down more and more through time, until the bottom layers slowly turn into rock.

Sandstone made from small grains of the minerals quartz and feldspar made from small grains of the minerals quartz and feldspar often form in layers often form in layers used as building stones used as building stones

Shale formed from clay that is compacted together by pressure formed from clay that is compacted together by pressure used to make bricks used to make bricks

Limestone made from the mineral calcite made from the mineral calcite used in concrete used in concrete

Sedimentary Rock pa.edu/earthsci/imag earchive/sedimentary. htm pa.edu/earthsci/imag earchive/sedimentary. htm pa.edu/earthsci/imag earchive/sedimentary. htm pa.edu/earthsci/imag earchive/sedimentary. htm Formed in layers as the result of moderate pressure on accumulated sediments. Formed in layers as the result of moderate pressure on accumulated sediments.

Metamorphic Metamorphic rocks are rocks that have changed into another kind of rock. Metamorphic rocks are rocks that have changed into another kind of rock. Tremendous heat and pressure causes them to change. Tremendous heat and pressure causes them to change.

Gneiss

Schist

gearchive/metamorphic.htm gearchive/metamorphic.htm gearchive/metamorphic.htm gearchive/metamorphic.htm Metamorphic Rocks : Formed from older "parent" rock (either igneous or sedimentary) under intense heat and/or pressure at considerable depths beneath the earth's surface. Metamorphic Rocks : Formed from older "parent" rock (either igneous or sedimentary) under intense heat and/or pressure at considerable depths beneath the earth's surface.