Igneous textures include the rock textures occurring in igneous rocks. Igneous textures are used by geologists in determining the mode of origin of igneous rocks and are used in rock classification. There are six main types of textures; phaneritic, aphanitic, porphyritic, glassy, pyroclastic and pegmatitic.

The textures of intrusive rocks formed from volcanic ash are categorized based on their content including bubbles and volcanic debris. Bubbles caused by low gas content form vesicular and amygdaloidal textures, which are somewhat porous.

If magma cools slowly, deep within the crust, the resulting rock is called intrusive or plutonic. The slow cooling process allows crystals to grow large, giving the intrusive igneous rock a coarse-grained or phaneritic texture.

Intrusive rock, also called plutonic rock, igneous rock formed from magma forced into older rocks at depths within the Earth’s crust, which then slowly solidifies below the Earth’s surface, though it may later be exposed by erosion.

Examine your rock for signs of visible grains. Igneous rocks are very dense and hard. They may have a glassy appearance. Metamorphic rocks may also have a glassy appearance. You can distinguish these from igneous rocks based on the fact that metamorphic rocks tend to be brittle, lightweight, and an opaque black color.

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

Felsic rocks have the highest content of silica, and are predominantly composed of the felsic minerals quartz and feldspar. These rocks (granite, rhyolite) are usually light coloured, and have a relatively low density. Intermediate rocks have a moderate content of silica, and are predominantly composed of feldspars.

The two main categories of igneous rocks are extrusive and intrusive. Extrusive rocks are formed on the surface of the Earth from lava, which is magma that has emerged from underground. Intrusive rocks are formed from magma that cools and solidifies within the crust of the planet.

The most common rock types in plutons are granite, granodiorite, tonalite, monzonite, and quartz diorite. Generally light colored, coarse-grained plutons of these compositions are referred to as granitoids.

Plutonic Igneous Rocks. Intrusive igneous rocks, formed by the slow solidification of magma deep below the surface and characterized by large crystals. Named after Pluto, the Roman god of the underworld. Examples include granite, gabbro and peridotite.

The main way to tell a plutonic rock is that it’s made of tightly packed mineral grains of medium size (1 to 5 mm) or larger, which means that it has phaneritic texture. In addition, the grains are of roughly equal size, meaning that it has an equigranular or granular texture.

In geology, a pluton is a body of intrusive igneous rock (also called plutonic rock) that is crystallized from magma slowly cooling below the surface of the Earth. The most common rock types in plutons are granite, granodiorite, tonalite, monzonite, and quartz diorite.