The Rock Cycle
Rock Cycle Interactive
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Bitesize: Rocks and Weathering
Rock Identification
Igneous rocks are formed from cooling magma. They are made of large or small crystals that are spread evenly throughout the rock. They may be light or dark, but usually light gray to black. There may also be pink, yellow, or black crystals in large grained rocks. Bubbles sometimes form if the rock cools very quickly. Some types of igneous rocks are: granite, basalt, gabbro, pumice, obsidian.
Sedementary rocks are pressed or cemented together from the grains that weather from other rocks. They may be any color with very fine or large sandy grains. They often have very clear layers that are easy to break apart. Fossils may be embedded in the rock. Some types of sedimentary rocks are: limestone, shale, chert, dolomite, coal.
Metamorphic rocks are formed from other rocks when they are put under great pressure and heat. They can be any color from pure white to solid black. Often they have fine grains of mica that flake off. They may also have layers of different minerals that are wavy like ribbons through the rock. They are usually very hard and the layers do not break apart easily. Some types of metamorphic rocks are: Slate, schist, gneiss, marble, quartzite.
Sedementary rocks are pressed or cemented together from the grains that weather from other rocks. They may be any color with very fine or large sandy grains. They often have very clear layers that are easy to break apart. Fossils may be embedded in the rock. Some types of sedimentary rocks are: limestone, shale, chert, dolomite, coal.
Metamorphic rocks are formed from other rocks when they are put under great pressure and heat. They can be any color from pure white to solid black. Often they have fine grains of mica that flake off. They may also have layers of different minerals that are wavy like ribbons through the rock. They are usually very hard and the layers do not break apart easily. Some types of metamorphic rocks are: Slate, schist, gneiss, marble, quartzite.