Earth Sciences 1022A/B Study Guide - Midterm Guide: Schist, Gneiss, Nonconformist
24 Jan 2017
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Pyrite an ore mineral of iron. Chalcopyrite an ore mineral of copper (wire) Galena an ore mineral of lead (car batteries) Magnetite an ore mineral of iron (steel) Igneous rocks rock that has solidified from mainly molten material (magma) Felsic magmas rich in silicon and amphiboles, quartz, and mica constitute over 95% of all igneous rocks (they crystallize according to bowen"s reaction series) and na-plagioclase minerals tend to produce light coloured rocks (granite and rhyolite) Intermediate magma composition between felsic and mafic (diorite and andesite) Mafic magmas rich in iron, magnesium, and. Calcium produce more olivine, pyroxene, amphibole, ca-plagioclase, and tend to produce darker rocks (gabbro and basalt) Ultramafic magma produces only ferromagnesian (mg, fe-rich) minerals like pyroxene and olivine (dunite, peridotite, pyroxenite) Phaneritic interlocking crystals of about equal size that are plainly visible to the unaided eye. Aphantic interlocking crystals are too small to see without a microscope (rocks appear structureless)
