Gabbro facts for kids
Gabbro is a type of dark, rough-grained igneous rock. Igneous rocks are formed when hot, melted rock material cools down and hardens. Gabbro forms deep inside the Earth when magma (melted rock) gets trapped and slowly cools into a solid mass of crystals.
Most of the Earth's oceanic crust (the part of the Earth's outer layer under the oceans) is made of gabbro. It forms at mid-ocean ridges, which are underwater mountain ranges where new crust is created. Gabbro crystals are usually larger than 1 mm, making it a coarse-grained rock. It is very similar in chemistry to basalt, which is a fine-grained rock that cools quickly at the Earth's surface.
The word gabbro can describe many different types of intrusive rocks. Think of it this way: gabbro is to basalt what granite is to rhyolite.
What Does the Name Gabbro Mean?
The name "gabbro" first appeared in the 1760s. It was used to describe rocks found in the Apennine Mountains in Italy. The name comes from a small village called Gabbro near Rosignano Marittimo in Tuscany, Italy.
Later, in 1809, a German geologist named Christian Leopold von Buch used the term more specifically. He used "gabbro" for rocks that geologists today might call "metagabbro." This means the gabbro had changed its form due to metamorphism, which is a process where rocks change because of heat, pressure, or chemical reactions.
What Is Gabbro Used For?
Gabbro often contains valuable metals and minerals. These can include chromium, nickel, cobalt, gold, silver, platinum, and copper sulfides. For example, the Merensky Reef, a famous rock layer, is the world's most important source of platinum, and it's found within gabbro.
In the construction world, gabbro is sometimes called black granite. People use it for things like countertops, floor tiles, and building facades. However, gabbro is a very hard rock, which makes it difficult to cut and shape. This limits how much it can be used in construction.
Images for kids
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Gabbro specimen
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Cizlakite sample
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Zuma Rock, Nigeria, a massive rock made of gabbro and granodiorite.
See also
In Spanish: Gabro para niños
