Schist, slate, and gneiss (pronounced like ‘nice’) are metamorphic rocks. They usually have a more hard, grainy texture than the other two types.
Metamorphic rocks are a combination of rock types, compressed together by high pressure and high temperatures. Clastic sedimentary rocks are rocks that people generally think of rocks that have pieces of other, pre-existing rocks that form a new rock. Sedimentary rocks often have lots of fossils in them because plants and animals get buried in the layers of sediment and turn into stone. Common examples of these rocks are limestone, sandstone, and shale. Sedimentary rocks are formed by layers of sediment (dirt, rock particles, etc.) being mixed and compressed together for extended periods of time. Because of all those air pockets, pumice can actually float! Pumice is a very porous rock because when the lava cooled, pockets of air were trapped inside. Granite, obsidian, basalt, and pumice are all common examples of igneous rocks. Igneous rocks are formed when hot magma cools rapidly, either by hitting underground air pockets (intrusive igneous rocks) or by flowing from the mouth of a volcano as lava on top of the ground (extrusive igneous rocks). They come in all colors: pink, green, orange, white, red.Īnd yet, scientists classify them all in only three groups! Keep reading to learn about the three types of rocks and the rock cycle. Rocks line river beds and jut above the landscape as mountain peaks they are fun to collect and sometimes are very beautiful.Įach rock is different some are smooth and round, some are sharp and dangerous. Rocks change very slowly under normal activity, but sometimes catastrophic events like a volcanic eruption or a flood can speed up the process. The difference is that, unlike the water cycle, you can’t see the rock cycle steps happening on a day-to-day basis. But rocks are always changing!Įxisting rocks undergo change as outlined in the rock cycle (which is similar to the water cycle). Rocks have a reputation for being solid, hard, and indestructible.
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