igneous rock(redirected from Igneous rocks)
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The term for a rock formed when molten rock cools and hardens. Extrusive, or volcanic, igneous rock cools on the surface as lava. Intrusive igneous rock forms when molten rock cools underground.
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|Noun||1.||igneous rock - rock formed by the solidification of molten magma|
rock, stone - material consisting of the aggregate of minerals like those making up the Earth's crust; "that mountain is solid rock"; "stone is abundant in New England and there are many quarries"
andesite - a dark grey volcanic rock
aplite - light-colored and fine-grained granitic rock consisting chiefly of quartz and feldspars
groundmass - (geology) the matrix of fine-grained crystalline material in which larger crystals are embedded
adesite - dark greyish extrusive rock
batholite, batholith, pluton, plutonic rock - large mass of intrusive igneous rock believed to have solidified deep within the earth
diorite - a granular crystalline intrusive rock
gabbro - one of a family of granular intrusive rocks
pegmatite - a form of igneous rock consisting of extremely coarse granite resulting from the crystallization of magma rich in rare elements
peridotite - a dark coarse-grained igneous rock consisting principally of olivine
rhyolite - very acid volcanic rock
volcanic rock - extrusive igneous rock solidified near or on the surface of the Earth
porphyritic rock, porphyry - any igneous rock with crystals embedded in a finer groundmass of minerals
sodalite - a vitreous mineral consisting of sodium aluminum silicate and sodium chloride in crystalline form; occurs in igneous rocks