Final answer:
A rock that melts and becomes magma will, upon cooling, solidify as an igneous rock. Igneous rocks are formed from the crystallization of molten material, while sedimentary and metamorphic rocks have different formation processes involving sedimentation and alteration by heat and pressure, respectively.
Step-by-step explanation:
If the pressure and temperature on a rock increase to the point where the rock melts and becomes magma, on cooling, it will become an igneous rock. Igneous rocks are formed from the solidification of molten material, either magma or lava. When this molten material cools and hardens, the result is a rock composed of interlocking mineral crystals, giving it a distinct texture and composition.
Metamorphic rocks, on the other hand, are formed from the alteration of pre-existing rocks through heat and pressure without melting. Whereas sedimentary rocks are formed from the compacting and cementing of sediment, which may include fragments from other rocks or the remains of organisms.
In summary, when melted rock material cools down, it crystallizes and forms igneous rocks, distinguishing them from other rock types by their origin and formation process.