Gabbro

Slow-cooling, coarse-grained gabbro has the same chemical composition and mineralogy as rapid-cooling, fine-grained basalt. Much of the Earth's oceanic crust is made of gabbro, formed at mid-ocean ridges.

Gabbro ( GAB-roh) is a phaneritic (coarse-grained), mafic (magnesium- and iron-rich), intrusive igneous rock formed from the slow cooling magma into a holocrystalline mass deep beneath the Earth's surface. Slow-cooling, coarse-grained gabbro has the same chemical composition and mineralogy as rapid-cooling, fine-grained basalt.

It is often called "black granite" commercially, just as other intrusive rocks are called "granite" in the dimension stone industry.

It is the most abundant rock in the deep oceanic crust.

It is usually black or dark green in color and composed mainly of the minerals plagioclase and augite.

It is usually black or dark green in color and composed mainly of the minerals plagioclase and augite. It is the most abundant rock in the deep oceanic crust.

Gabbro is a coarse-grained, dark-colored, intrusive igneous rock . It is usually black or dark green in color and composed mainly of the minerals plagioclase and augite.

Zuma Rock is a large natural monolith, or inselberg, an igneous intrusion composed of gabbro and granodiorite and of Precambrian age, located in Madalla, a town in Niger State, Nigeria.

Zuma Rock is a large natural monolith, or inselberg, an igneous intrusion composed of gabbro and granodiorite and of Precambrian age, located in Madalla, a town in Niger State, Nigeria.