gabbro

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Any of several medium- or coarse-grained rocks that consist primarily of plagioclase feldspar and pyroxene.

Gabbros are found widely on the Earth and on the Moon. They are sometimes quarried for dimension stone (“black granite”), but the direct economic value of gabbro is minor. Far more important are the nickel, chromium, and platinum minerals that occur almost exclusively in association with gabbroic or related rocks. Magnetite (iron) and ilmenite (titanium) are also found in gabbroic complexes.

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monzonite - Type of igneous rock that contains abundant and approximately equal amounts of plagioclase and potash feldspar, as well as other minerals.

mafic rock - In geology, any igneous rock dominated by the silicates pyroxene, amphibole, olivine, and mica.

augite - Most common pyroxene mineral, occurring chiefly as blocky crystals in basalts, gabbros, andesites, and various other dark igneous rocks.

crust - Outermost solid part of the Earth, essentially composed of a range of igneous and metamorphic rock types.

ilmenite - Iron-black, heavy, metallic oxide mineral, composed of iron and titanium oxide (FeTiO3), which is the major source of titanium.

More on "gabbro" from the 32 Volume Encyclopædia Britannica:

gabbro - any of several medium- or coarse-grained rocks that consist primarily of plagioclase feldspar and pyroxene. Essentially, gabbro is the intrusive (plutonic) equivalent of basalt, but whereas basalt is often remarkably homogeneous in mineralogy and composition, gabbros are exceedingly variable. Gabbros are found widely on the Earth and on the Moon as well. Gabbros are sometimes quarried for ...

ocean - S latitude, a series of sheet flow eruptions (possibly since the mid-1960s) have covered more than 220 square kilometres of seafloor to an average depth of 70 metres.

diorite - medium- to coarse-grained intrusive igneous rock that commonly is composed of about two-thirds plagioclase feldspar and one-third dark-coloured minerals, such as hornblende or biotite. The presence of sodium-rich feldspar, oligoclase or andesine, in contrast to calcium-rich plagioclase, labradorite or bytownite, is the main distinction between diorite and gabbro. The extrusive (volcanic) ...

mafic rock - in geology, igneous rock that is dominated by the silicates pyroxene, amphibole, olivine, and mica. These minerals are high in magnesium and ferric oxides, and their presence gives mafic rock its characteristic dark colour. Mafic rock is commonly contrasted with felsic rock, in which light-coloured minerals predominate. Common mafic rocks include basalt and its coarse-grained intrusive ...

augite - the most common pyroxene mineral (a silicate of calcium, magnesium, iron, titanium, and aluminum). It occurs chiefly as thick, tabular crystals in basalts, gabbros, andesites, and various other dark-coloured igneous rocks. It also is a common constituent of lunar basalts and meteorites rich in basaltic material. Augites may be found in certain metamorphic rocks, notably marbles. For chemical ...

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