Latite
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Latite is an igneous, volcanic (extrusive) rock, with aphanitic-aphyric to aphyric-porphyritic texture. Its mineral assemblage is usually alkali feldspar and plagioclase (in a ratio < 1:4). Quartz is absent in a feldspathoid-bearing latite, and olivine is absent in a quartz-bearing latite. Biotite, hornblende, pyroxene and scarce olivine or quartz are common accessory minerals.
Rhomb porphyries are an unusual variety with gray-white porphyritic rhomb shaped phenocrysts enbedded in a very fine grained red-brown matrix. The composition of rhomb porphyry places it in the trachyte - latite classification of the QAPF diagram.
