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Extrusive igneous rocks have come to the surface when cooling down. Intrusive igneous rocks stay within the earth. This difference is important.

When a magma comes to the surface, it's called a lava. On the surface, the lava will be subject to cooling by wind and water. This will happen fast. When a magma stays inside the earth, it will cool down considerably slower, because it has to radiate it's heat to the rest of the earth. This doesn't go fast because while water and air can flow, rock can't.

The texture of an igneous rock has everything to do with the cooling speed. As a magma or a lava cools, it forms crystals. When the cooling happens relatively fast, these crystals do not have a lot of time to grow together, so you will get a lot of small crystals. When the cooling is very slow, the crystals will have more time to grow, and the crystal size will be a lot bigger.

Take for instance granite. If you've ever seen it, you know you can see the crystals with the naked eye, because they are very large. Basalt, on the other hand has a very fine structure, you can't see the crystals without magnifying equipment like a microscope.

So there you have it: an extrusive igneous rock will have a very fine texture, with small crystal sizes, an intrusive igneous rock will have a very coarse texture, with large crystal sizes.

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Are large crystals intrusive or extrusive igneous rock?

Large crystals are typically characteristic of intrusive igneous rocks, which form beneath the Earth's surface from slow cooling of magma. Extrusive igneous rocks cool quickly at or near the Earth's surface, resulting in smaller crystals or glassy textures.


What is the different between extrusive and intrusive rocks?

Intrusive: An intrusive igneous rock is formed from magma undergroundExtrusive: An extrusive igneous rock is formed from lava outside of the volcano.


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

"intrusive" means forced into something, "extrusive" means forced out onto the surface. The igneous magma reaching the surface is therefore extrusive , producing extrusive igneous rocks, and all the rest of the magma is intrusive, producing intrusive igneous rocks.


Is schist an intrusive or extrusive rock?

Neither, Igneous rock is either intrusive or extrusive. Thats what intrusive and extrusive is... A igneous rock.


What is the difference between exrusive an intrsive igneous rock?

Extrusive igneous rocks are formed from lava that cools quickly on the Earth's surface, resulting in fine-grained textures. Intrusive igneous rocks are formed from magma that cools slowly beneath the Earth's surface, resulting in coarse-grained textures.


What igneous rocks are both intrusive and extrusive?

The igneous rocks that can be both intrusive and extrusive are known as porphyritic rocks. These rocks form when magma partially cools underground (intrusive) before being erupted onto the Earth's surface where the remaining magma cools quickly (extrusive). This dual cooling process creates distinctive textures in the rock, with larger crystals (phenocrysts) embedded in a finer-grained matrix.


What are the main two types of igneous rocks?

Igneous rocks are classified as either extrusive or intrusive. Extrusive rocks form from lava at or above the ground, and intrusive rocks form from magma below the ground. Granite is intrusive, pumice is extrusive.


Is marble an extrusive or an intrusive rock?

Neither. The terms intrusive and extrusive apply to igneous rocks; marble is metamorphic.


What does extrusive rock means?

Extrusive igneous rock is one of two different types of igneous rocks. The other kind is intrusive igneous rock. Intrusive igneous rock is formed when magma in Earth's lithosphere cools and hardens. Extrusive igneous rock is formed when lava on Earth's surface cools and hardens.


Is a metamorphic rock intrusive or extrusive?

It is neither. Intrusive and extrusive are terms used to describe igneous rock.


Is extrusive a rock?

Igneous rocks can be categorized as either extrusive or intrusive.


What are the types of Igneous rock?

extrusive and intrusive