Extrusive Igneous Rocks
Extrusive igneous rocks, additionally referred to as volcanic rocks, are fashioned on the crust’s surface due to the partial melting of rocks within the mantle and crust. Extrusive Igneous Rocks are listed below.
Obsidian
Obsidian is an igneous rock that forms when molten rock material cools so rapidly that atoms are unable to arrange themselves into a crystalline structure. It is an amorphous material known as a "mineraloid." The result is a volcanic glass with a smooth uniform texture that breaks with a conchoidal fracture .
Pillow Lava
Pillow lava is a type of basaltic lava that forms underwater, typically in the ocean. It gets its name from the characteristic pillow-like shapes...
Basalt
Basalt is the most common rock on Earth’s surface. Specimens are black in color and weather to dark green or brown. Basalt is rich in iron and magnesium and is mainly composed of olivine, pyroxene, and plagioclase. Most specimens are compact, fine-grained, and glassy. They can also be porphyritic, with phenocrysts of olivine, augite, or plagioclase. Holes left by gas bubbles can give basalt a coarsely porous texture.
Volcanic Bomb
Volcanic bomb is pyroclastic rock that is a cooling of a mass of lava it flies thorough the air after eruption. If it is...
Pyroxenite
Pyroxenite is an ultramafic igneous rock that contain pyroxene group minerals such as augite, diopside, hypersthene, bronzite or enstatite. This is a coarse-grained rock...
