What are the three characteristics of extrusive igneous rocks?

What are the three characteristics of extrusive igneous rocks? Extrusive igneous rocks erupt onto the surface, where they cool quickly to form small crystals. Some cool so quickly that they form an amorphous glass. These rocks include: andesite, basalt, dacite, obsidian, pumice, rhyolite, scoria, and tuff.

What are the characteristics of extrusive rocks?

Extrusive rocks are usually distinguished from intrusive rocks on the basis of their texture and mineral composition. Both lava flows and pyroclastic debris (fragmented volcanic material) are extrusive; they are commonly glassy (obsidian) or finely crystalline (basalts and felsites).

What are the characteristics of intrusive and extrusive igneous rocks?

Intrusive igneous rocks cool from magma slowly in the crust. They have large crystals. Extrusive igneous rocks cool from lava rapidly at the surface. They have small crystals.

What are 3 characteristics of igneous rocks?

Igneous rocks can be easily identified with their texture, density, colour, and mineral composition. Its texture depends on the shape, size, time period to cool down and solidify, and the arrangement of crystals in the rock.

What common characteristic do intrusive and extrusive rocks have in common?

Extrusive rocks and intrusive rocks both form when hot molten material crystallizes. However, extrusive rocks form from lava at the surface of the Earth, whereas intrusive rocks form from magma underground, often relatively deep in the Earth.

What is the texture of the extrusive rocks?

The texture of extrusive rocks is characterized by fine-grained crystals indistinguishable to the human eye, described as aphantic. Crystals in aphantic rocks are small in size due to their rapid formation during eruption.

What kind of texture do extrusive igneous rocks have?

Extrusive igneous rocks have a fine-grained or aphanitic texture, in which the grains are too small to see with the unaided eye. The fine-grained texture indicates the quickly cooling lava did not have time to grow large crystals. These tiny crystals can be viewed under a petrographic microscope [1].

What is the difference between extrusive igneous rocks and intrusive igneous rocks quizlet?

The difference between intrusive and extrusive igneous is that, intrusive rock is one that forms when magma cools within Earth. Extrusive igneous rock is one that, forms when lava cools on Earths surface.

What are the 5 characteristics of igneous rocks?

What are the 3 main differences between intrusive and extrusive igneous rocks?


Extrusive Igneous rocks Intrusive Igneous rocks
They are formed by the cooling of molten magma on the earth’s surface. They are formed when magma solidifies within the the earth’s crust.
These rocks are smooth, crystalline and fine grained. These rocks are coarse textured, hard rocks with large crystals.

Are extrusive rocks coarse grained?

Extrusive or volcanic rocks crystallize from lava at the earth’s surface. Magmas and their resultant plutonic rock bodies cool and crystallize slowly and are characterized by coarse-grained texture, in which the mineral crystals are visible to the unaided eye.