The type of rock formed from the quick cooling of lava on the surface is called extrusive igneous rock.

Here's why:

* Igneous means "fire-formed," and these rocks are formed from the cooling and solidification of magma (underground) or lava (above ground).

* Extrusive refers to the process of the molten rock erupting onto the Earth's surface.

Because the lava cools quickly, the minerals in the rock have less time to crystallize, resulting in smaller crystals. This gives extrusive igneous rocks a fine-grained texture. Some common examples of extrusive igneous rocks include:

* Basalt: A dark, dense rock often found in volcanic flows.

* Rhyolite: A light-colored, silica-rich rock with a glassy texture.

* Andesite: An intermediate-colored rock between basalt and rhyolite.

Let me know if you'd like to know more about igneous rocks!