Why Does Granite Have Bigger Crystals Than Basalt

If magma cools quickly for example when basalt lava erupts from a volcano then many crystals form very quickly and the resulting rock is fine grained with crystals usually less than 1mm in size.

Why does granite have bigger crystals than basalt.

Obsidian and granite are igneous rocks so called because they were formed from the molten magma of volcanoes. It depends on the type of igneous rock. Yes because granite is a slow cooling rock therefore the crystals have a lot of time to form while basalt is a fast cooling rock therefore thecrystals don t have much time to form and develop. Intrusive igneous rocks have cooled slowly from magma extrusive rocks have.

Obsidian is not a genuine mineral or rock it is a natural glass that contains microscopic mineral crystals. Beyond that their similarities end. The crystals in granite being intrusive in nature will be larger than those in basalt an extrusive igneous rock. This slow cooling gives time for crystals to grow making it more coarsely grained than an extrusive rock.

The crystals in granite being intrusive in nature will be larger than those in basalt an extrusive igneous rock. Granite contains more water and minerals that melt at lower temperatures rocks that are rich in which 2 elements melt at higher temperatures than rocks that contain higher levels of silicon. Like gabbro granite and diorite basalt is an igneous rock and is also the most abundant bedrock on earth including under the surface and within ocean basins. Basalt on the other hand has a smooth texture from rapid cooling usually by water.

Intrusive igneous rocks such as granite have large crystals extrusive igneous rocks may have small crystals as in basalt or no crystals as in pumice. Basalt rocks have fine grained crystals while gabbro is made up of much larger coarse grained pieces. What s the most obvious difference between basalt and gabbro. Granite is an intrusive rock that is formed when magma cools inside the crust.

Intrusive igneous rocks have cooled slowly from magma extrusive rocks have. Crystals have more time to grow to larger size.