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acidic igneous rock original

broader	acidic igneous material original igneous rock original
definition	Igneous rock with more than 63 percent SiO2.
narrower	dacite original granitoid original quartz rich igneous rock original rhyolitoid original

alkali olivine basalt original

broader	basalt original
definition	Alkali olivine basalt is silica-undersaturated, characterized by the absence of orthopyroxene, absence of quartz, presence of olivine, and typically contains some feldspathoid mineral, alkali feldspar or phlogopite in the groundmass. Feldspar phenocrysts typically are labradorite to andesine in composition. Augite is rich in titanium compared to augite in tholeiitic basalt. Alkali olivine basalt is relatively rich in sodium.

alkali feldspar granite original

broader	granitoid original
definition	Granitic rock that has a plagioclase to total feldspar ratio less than 0.1. QAPF field 2.

alkali feldspar rhyolite original

broader	rhyolitoid original
definition	Rhyolitoid in which the ratio of plagioclase to total feldspar is less than 0.1. QAPF field 2.

alkali feldspar syenite original

broader	alkali feldspar syenitic rock original
definition	Alkali feldspar syenitic rock that contains 0-5 percent quartz and no feldspathoid in the QAPF fraction. QAPF field 6.

alkali feldspar syenitic rock original

broader	syenitoid original
definition	Syenitoid with a plagioclase to total feldspar ratio of less than 0.1. QAPF fields 6, 6*, and 6'.
narrower	alkali feldspar syenite original foid bearing alkali feldspar syenite original quartz alkali feldspar syenite original

alkali feldspar trachyte original

broader	alkali feldspar trachytic rock original
definition	Trachytoid that has a plagioclase to total feldspar ratio less than 0.1, between 0 and 5 percent quartz in the QAPF fraction, and no feldspathoid minerals. QAPF field 6.

alkali feldspar trachytic rock original

broader	trachytoid original
definition	Trachytoid that has a plagioclase to total feldspar ratio less than 0.1. QAPF fields 6, 6', and 6*.
narrower	alkali feldspar trachyte original foid bearing alkali feldspar trachyte original quartz alkali feldspar trachyte original

amphibolite original

broader	metamorphic rock original
definition	Metamorphic rock mainly consisting of green, brown or black amphibole and plagioclase (including albite), which combined form 75 percent or more of the rock, and both of which are present as major constituents. The amphibole constitutes 50 percent or more of the total mafic constituents and is present in an amount of 30 percent or more; other common minerals include quartz, clinopyroxene, garnet, epidote-group minerals, biotite, titanite and scapolite.

andesite original

broader	fine grained igneous rock original intermediate composition igneous rock original
definition	Fine-grained igneous rock with less than 20 percent quartz and less than 10 percent feldspathoid minerals in the QAPF fraction, in which the ratio of plagioclase to total feldspar is greater 0.65. Includes rocks defined modally in QAPF fields 9 and 10 or chemically in TAS field O2 as andesite. Basalt and andesite, which share the same QAPF fields, are distinguished chemically based on silica content, with basalt defined to contain less than 52 weight percent silica. If chemical data are not available, the color index is used to distinguish the categories, with basalt defined to contain greater than 35 percent mafic minerals by volume or greater than 40 percent mafic minerals by weight. Typically consists of plagioclase (frequently zoned from labradorite to oligoclase), pyroxene, hornblende and/or biotite. Fine grained equivalent of dioritic rock.
narrower	boninite original