How are the 3 major groups of rocks different?

Answer 1

The three main groups, igneous, metamorphic and sedimentary are all part of the rock cycle. They are different in the way they formed and in their properties. Igneous rocks are formed when magma/lava cools and solidifies; metamorphic rocks are formed when a buried existing rock is heated up by the Earth's natural heat and is altered in its structure; and sedimentary rocks are formed when existing igneous or metamorphic rocks are weathered and eroded, and the resulting rock fragments are compacted together to produce a new rock. Each of these 3 types of rock can become any of the other types; ie an igneous rock can be subjected to further heating, which alters its structure, and turn into a metamorphic rock; or a sedimentary rock could be drawn back down into the Earth's molten mantle via a subduction zone, undego melting, and then later rise back to the surface and solidify to become an igneous rock.