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Felsic magmas and lavas have lower temperatures of melting and solidification than mafic magmas and lavas. Felsic rocks are usually light in color and have specific gravities less than 3. The most common felsic rock is granite. Common felsic minerals include quartz, muscovite, orthoclase, and the sodium-rich plagioclase feldspars (albite-rich).
Mafic enclave in granite rock, at Yosemite National Park Granite forms from silica-rich ( felsic ) magmas. Felsic magmas are thought to form by addition of heat or water vapor to rock of the lower crust , rather than by decompression of mantle rock, as is the case with basaltic magmas. [ 19 ]
Alkali feldspar granite – Type of igneous rock rich in alkali feldspar; Anorthosite – Mafic intrusive igneous rock composed predominantly of plagioclase; Aplite – Fine-grained intrusive igneous rock type similar to granite; Basalt – Magnesium- and iron-rich extrusive igneous rock
A mafic mineral or rock is a silicate mineral or igneous rock rich in magnesium and iron. Most mafic minerals are dark in color, and common rock-forming mafic minerals include olivine, pyroxene, amphibole, and biotite. Common mafic rocks include basalt, diabase and gabbro. Mafic rocks often also contain calcium-rich varieties of plagioclase ...
Its silica content (by one common classification) would make it a mafic rock in chemical terms, but an ultramafic rock in mineralogical terms, because it would be entirely composed of a mafic mineral. [6] Some examples of felsic rocks include granite and rhyolite, while examples of mafic rocks include gabbro and basalt. [1]
Granite and rhyolite are the most common silicic rocks. Silicic is the group of silicate magmas which will eventually crystallise a relatively small proportion of ferromagnesian silicates , such as amphibole , pyroxene , and biotite .
mafic A silicate mineral or rock that is rich in magnesium and iron. A mnemonic term for the ferromagnesian and other non-felsic minerals actually present in an igneous rock rich in dark (ferromagnesian) minerals (greater than 60% by volume). Basic [alkali gabbro (alkali basalt), syeno-gabbro (trachybasalt), gabbro (basalt and dolerite)]. magma
Diorite is an intrusive igneous rock composed principally of the silicate minerals plagioclase feldspar (typically andesine), biotite, hornblende, and sometimes pyroxene.The chemical composition of diorite is intermediate, between that of mafic gabbro and felsic granite.