Igneous rock
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Igneous rock, or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rocks are formed through the cooling and solidification of magma or lava.
Geologic provinces of the world (USGS) Shield Platform Orogen Basin Large igneous province Extended crust Oceanic crust: 0–20 Ma 20–65 Ma >65 Ma
Volcanic eruptions of lava are major sources of igneous rocks. (Mayon volcano in the Philippines, erupting in 2009)
Natural columns of igneous rock separated from each other by columnar joints, in Madeira
Formation of igneous rock
Lamprophyre
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Lamprophyres are uncommon, small-volume ultrapotassic igneous rocks primarily occurring as dikes, lopoliths, laccoliths, stocks, and small intrusions. They are alkaline silica-undersaturated mafic or
Minette (a type of lamprophyre), from Jáchymov in the Czech Republic
Microscope view (long dimension 2 mm) of a thin section of minette from the Colorado Plateau. Magnesium-rich biotite (P, phlogopite) and clinopyroxene (C) phenocrysts in a groundmass of alkali feldspar, pyroxene, and iron-titanium oxides.
A dike of minette near Shiprock, Navajo Volcanic Field