Latite

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Latite
Volcanic rock
Latit - Boxberg, Hocheifel.jpg
Photomicrograph of thin section of latite (in plane polarised light)
Photomicrograph of thin section of latite (in cross polarised light)

Latite is an igneous, volcanic rock, with aphanitic-aphyric to aphyric-porphyritic texture. Its mineral assemblage is usually alkali feldspar and plagioclase in approximately equal amounts. Quartz is less than five percent and is absent in a feldspathoid-bearing latite, and olivine is absent in a quartz-bearing latite. When quartz content is greater than five percent the rock is classified as quartz latite.[1] 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 embedded in a very fine grained red-brown matrix. The composition of rhomb porphyry places it in the trachyte - latite classification of the QAPF diagram.

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