Igneous Rocks Like Granite

Similar to granite in formation.

Igneous rocks like granite.

Any intrusive igneous rock such as gabbro or diorite. Rocks labeled as granite in laymen applications can be several other rocks including syenite tonalite and monzonite. What are igneous rocks. Somewhat similar in appearance.

All magma develops underground in the lower crust or upper mantle because of the intense heat there. It forms from the slow crystallization of magma below earth s surface. The two best known igneous rock types are basalt and granite which have distinctly different compositions and textures. If they erupt from volcanoes onto the surface as lava they are called extrusive rocks by contrast intrusive rocks are formed from magma that cools underground.

Igneous rocks form when magma molten rock cools and crystallizes either at volcanoes on the surface of the earth or while the melted rock is still inside the crust. Feldspar quartz amphiboles and pyroxenes together called dark minerals by geologists as well as olivine along with the softer mineral mica. There are two basic types. They are intrusive and contain a mixture of minerals including hornblende pyroxene feldspar and sometimes quartz.

When the chemical analysis of an acid rock like granite and of a basic rock like basalt are compared important differences are seen such as the greater proportion of silica and alkalies na 2 o and k 2 o in the acid rock and the higher content of lime magnesia and iron oxide in the basic rock. Igneous rocks are those that form via the process of melting and cooling. Granite is a light colored igneous rock with grains large enough to be visible with the unaided eye. Similar to granite in composition.

Igneous rocks can have many different compositions depending on the magma they cool from. Granite ˈ ɡ r æ n ɪ t is a common type of felsic intrusive igneous rock that is granular and phaneritic in texture. Granites can be predominantly white pink or gray in color depending on their mineralogy the word granite comes from the latin granum a grain in reference to the coarse grained structure of such a completely crystalline rock. If the intrusive rock cooled underground but near the surface it is called subvolcanic or hypabyssal and often has visible but tiny mineral grains.

Diorite granite gneiss and. The main minerals in igneous rocks are hard primary ones. Igneous rocks are formed from the solidification of molten rock material. They appear light colored with some dark spots.

Examples of intrusive igneous rocks are diabase diorite gabbro granite pegmatite and peridotite. Diorites are the coarse grained igneous rocks just like the gabbros and granite. To avoid these complications the following figure presents a simplified version of igneous rock nomenclature focusing on the four main groups which is adequate for an introductory student.