How rocks was form?
Depends on the type of rock... There is a rock cycle.
Are sedimentary rocks form from rock and mineral fragments and metamorphic rocks form from existing rocks?
There is no such thing as an "exclusive" rock. However, there are extrusive rocks. These are divisions of igneous rocks, or rocks that form from molten rock. Intrusive rocks form from molten rock that has cooled underground. They can also be called plutonic rocks. Extrusive rocks, also called volcanic rocks, form from molten rock that has formed at or above the surface.
Sedimentary rocks form from layers of sand, silt or clay, sometimes mixed with pebbles, and the bodies of living things (that may the be fossilised) The rocks are often quite soft. Metamorphic rocks form when rocks (usually sedimentary rocks) are subjected to extreme heat and/or pressure, usually deep underground. The rocks are changed in form, often becoming harder. Fossils are usually destroyed by the process.
The three kinds of rocks by their method of formation are IGNEOUS rocks, SEDIMENTARY rocks and METAMORPHIC rocks. Igneous rocks cool from magma or lava. Sedimentary rocks form by the deposition of particulates and silt. Metamorphic rocks form from rocks (usually sedimentary) that are compressed and heated underground.
No. Rocks can be classified into three general groups: Igneous rocks, which form from molten rock Sedimentary rocks, which form from broken-down rocks turned back into stone Metamorphic rocks, which form as rocks change due to heat and pressure without melting. Igneous rocks are further divided into intrusive rocks, which cool underground, and extrusive rocks, which cool above ground. Only extrusive igneous rocks are considered volcanic.