Why Does Basalt Have Smaller Crystals Than Granite

Crystals have more time to grow to larger size.

Why does basalt have smaller crystals than granite.

Cools more slowly and crystals are bigger which means they are coarse grained. You may use your identification charts rhyolite cooled quicker than granite. Granite is an intrusive rock that is formed when magma cools inside the crust. Basalt cooled quickly and is therefore fine grained to even glassy with or without phenocrysts individual large crystals.

How can you distinguish basalt from a sill or buried lava flow. It mainly occurs on the floor of the ocean as magma solidifies quickly coming in contact with cool ocean water. Basalt scoria andesitic diorite andesite granitic granite rhyolite pumice obsidian. This coarse grain makes granite a favorite of rock climbers.

Why does rhyolite have smaller crystals than granite. 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. Among other differences the nature of these rocks reveals that basalt is basic in nature whereas granite is acidic in nature. The difference is the texture.

Under the ground so they cools slow and that s why they have large crystals. These extrusive rocks are formed from magma at or above the surface of the planet and generally display smaller mineral crystals or. This slow cooling gives time for crystals to grow making it more coarsely grained than an extrusive rock. Gabbro cooled slowly and is entirely composed of large larger crystals without any glassy or very fine grained rock material.

Basalt on the other hand has a smooth texture from rapid cooling usually by water. They cools so fast and that s why they have small crystals than granite. 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.