Basalt
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Basalt ; US: buh-SALT is an aphanitic extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron exposed at or very near the surface of a rocky planet or moo
QAPF diagram with basalt/andesite field highlighted in yellow. Basalt is distinguished from andesite by SiO2 < 52%.
Vesicular basalt at Sunset Crater, Arizona. US quarter (24mm) for scale.
Columnar basalt flows in Yellowstone National Park, US
Pyroxenite
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Pyroxenite is an ultramafic igneous rock consisting essentially of minerals of the pyroxene group, such as augite, diopside, hypersthene, bronzite or enstatite. Pyroxenes have the general formula XY2O
Pyroxenite from Rustenburg, South Africa
Metamorphosed (serpentinized) clinopyroxenite, made of green diopside, from the Shetland ophiolite, Unst, Scotland