What type of rock forms from the cooling and solidification of magma or lava?

Igneous.

The type of rock that forms from the cooling and solidification of magma or lava is known as igneous rock. Igneous rocks are one of the three main types of rocks, along with sedimentary and metamorphic rocks. They form through the process of crystallization, where molten material from the Earth’s mantle or crust cools and solidifies into a solid rock form.

There are two primary types of igneous rocks: intrusive (or plutonic) and extrusive (or volcanic). Intrusive igneous rocks form when magma cools slowly beneath the Earth’s surface, allowing large crystals to develop. One of the most common examples of intrusive igneous rock is granite, which is widely used in construction and architecture due to its durability and attractive appearance. Granite’s crystals are often easily visible because of the slow cooling process, which allows them to grow larger.

Extrusive igneous rocks, on the other hand, form when lava is expelled from a volcano or fissure and cools rapidly on the Earth’s surface. Because of this rapid cooling, the crystals in extrusive rocks are much smaller and may not be visible to the naked eye. Basalt is the most common example of extrusive igneous rock, frequently found in oceanic crust and volcanic regions. Basalt has a fine-grained texture and is often dark in color.

The composition of igneous rocks can vary depending on the chemical makeup of the magma or lava from which they are formed. Common minerals found in igneous rocks include quartz, feldspar, and mica. Igneous rocks are essential in understanding Earth’s geological history, as their formation often relates to tectonic activity, volcanic eruptions, and the creation of new crust.