Mafic rocks

thumb|Gabbro specimen from Duluth, Minnesota thumb|Photomicrograph of a [[thin section of gabbro]]

thumb|Diabase

thumb|Minette (a type of lamprophyre), from Jáchymov in the Czech Republic

Basanite () is an igneous, volcanic (extrusive) rock with aphanitic to porphyritic texture. It is composed mostly of feldspathoids, pyroxenes, olivine, and calcic plagioclase and forms from magma low in silica and enriched in alkali metal oxides that solidifies rapidly close to the Earth's surface.

thumb|right|Sample of norite thumb|right|Shocked norite found in the Taurus-Littrow valley on the moon during the [[Apollo 17 mission (sample 78236).]] Norite is a mafic intrusive igneous rock composed largely of the calcium-rich plagioclase labradorite, orthopyroxene, and olivine. The name norite is derived from Norway, by its Norwegian name Norge.

Troctolite (from Greek τρώκτης 'trout' and λίθος 'stone') is a mafic intrusive rock type. It consists essentially of major but variable amounts of olivine and calcic plagioclase along with minor pyroxene. It is an olivine-rich anorthosite, or a pyroxene-depleted relative of gabbro. However, unlike gabbro, no troctolite corresponds in composition to a partial melt of peridotite. Thus, troctolite is necessarily a cumulate of crystals that have fractionated from melt.

Tachylite ( ; also spelled tachylyte) is a form of basaltic volcanic glass. This glass is formed naturally by the rapid cooling of mafic lava or magma. It is a type of mafic igneous rock that is decomposable by acids and readily fusible. The color is a black or dark-brown, and it has a greasy-looking, resinous luster. It is very brittle and occurs in dikes, veins, and intrusive masses. The word originates from the Ancient Greek , meaning "swift".

Hawaiite is an olivine basalt with a composition between alkali basalt and mugearite. It was first used as a name for some lavas found on the island of Hawaii.

variety of high-magnesium olivine basalt that is very rich in the mineral olivine

thumb|upright=1.35|Peridotite [[xenoliths (green) in phonotephrite from Peridot Mesa, Arizona]] Phonotephrite or phono-tephrite is a strongly alkaline volcanic rock with a composition between phonolite and tephrite. This unusual igneous rock contains 7–12% alkali content and 45–53% silica content (see TAS diagram). It can be described as a mafic phonolite or a potassic tephrite. Phonotephrite lava flows and volcanic cones have been identified in Antarctica (e.g. Mount Erebus), Europe (e.g. Mount Vesuvius), North America (e.g. Satah Mountain volcanic field) and Africa (e.g. Jbel Saghro).

thumb | right | Ankaramite lava flow Ankaramite is volcanic rock type of mafic composition. It is a dark porphyritic variety of basanite containing abundant pyroxene and olivine phenocrysts. It contains minor amounts of plagioclase and accessory biotite, apatite, and iron oxides.

Tephriphonolite or tephri-phonolite is a mafic to intermediate extrusive igneous rock in composition between phonotephrite and phonolite. It contains 9–14% alkali content and 48–57% silica content (see TAS diagram). Tephriphonolite is roughly equivalent to tephritic phonolite of the QAPF classification.