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latite A porphyritic, extrusive igneous rock containing euhedral phenocrysts of calcium-rich plagioclase feldspar, accompanied by lesser amounts of biotite, magnesium clinopyroxene, magnesium orthopyroxene, iron-titanium oxides, and olivine phenocrysts set in a trachytic groundmass dominated by alkali feldspar. Plagioclase accounts for 40–60% of the total feldspar content of the rock. Latites are the volcanic equivalents of monozonites and, as such, they are members of the calc-alkaline magma series. The term is sometimes used to describe potassium rich andesites.