Final answer:
Solidified pieces of magma or lava such as granite or basalt are classified as Igneous rocks, which are formed from cooled, solidified molten material.
Step-by-step explanation:
The solidified pieces of magma or lava such as granite or basalt that make up much of the Earth's crust are classified as Igneous rock. Igneous rocks are created when hot molten material from the Earth's core cools and solidifies. This process can happen beneath the Earth's surface to form intrusive igneous rocks like granite, characterized by coarse-grained crystals that give a sugary appearance. Alternatively, when magma reaches the surface and becomes lava, the rapid cooling creates extrusive igneous rocks like basalt, which generally have finer grains.
Other rock types include sedimentary rocks, which are formed by the cementing of rock fragments or organic material, and metamorphic rocks, which arise from the alteration of igneous or sedimentary rock under high temperature or pressure. However, in the case of the rocks described in the student's question, igneous is the correct answer.