Metamorphic rocks are rocks that are formed under extremely high heat and pressure. Metamorphic rocks often times have fine and banded grain, and this is because of the two types of metamorphic rock. These types are called foliated rocks and non-foliated rocks. Foliated rocks are metamorphic rocks that have grains that split into layers, because their grains are arranged into those layers. Non-foliated rocks are metamorphic rocks that do not split into layers because their grains are arranged randomly. With that in mind, I can tell you how they form in better detail. You see, metamorphic rocks are formed when collisions of Earth's plates push existing rocks into the ground. Pockets of magma put extreme heat into the rock. When the rocks is very deep, the pressure is greater. With this combination of heat and pressure, the mineral composition of the rock changes. So does the crystal structure. Because of this, new rocks are formed, metamorphic rocks.
Below is a chart of different types of metamorphic rock.
Below is a chart of different types of metamorphic rock.
Metamorphic rocks are very useful in certain things and jobs. For example, marble is used in sculpting and carving. Structures like the statue of Abraham Lincoln in the Lincoln Memorial in Washington DC. Slate is used for, flooring, roofing, sidewalks, chalkboards, and trim for stone buildings. Some metamorphic rocks can be found in everyday objects such as soap. Schist is commonly used for decorating gardens, paving, and rarely, sculpting. There are many more uses, but those are some great examples. With the three types of rocks and the ways to classify them out of the way, we can finally go to probably the most important page, the rock cycle.