Skip to content
Science, Maths & Technology


Updated Thursday, 28th September 2006

A brief description of the nature of gabbro

This page was published over five years ago. Please be aware that due to the passage of time, the information provided on this page may be out of date or otherwise inaccurate, and any views or opinions expressed may no longer be relevant. Some technical elements such as audio-visual and interactive media may no longer work. For more detail, see our Archive and Deletion Policy

Gabbro is a coarse-grained, intrusive igneous rock. It contains interlocking crystals, larger than rice grains, which are randomly oriented. It is dark green to black. It contains mainly mafic (dark coloured) minerals.

Gabbro Copyrighted  image Icon Copyright: The Open University

How was it formed?
Gabbro forms deep within the Earth’s crust, often from very large masses of magma that do not reach the surface. Slow cooling produces the large crystals. Gabbro forms under similar conditions to granite and diorite.

But unlike granite, gabbro forms from magma that is rich in iron and magnesium, and poor in quartz (silica).


Get closer to geology






Related content (tags)

Copyright information

For further information, take a look at our frequently asked questions which may give you the support you need.

Have a question?