Plagioclase

porphyritic. The mineral assemblage is uisually quartz, alkali feldspar an plagioclase (in a ratio > 1:2—see the QAPF diagram). Biotite an hornblende are common...

aboot three-quarters o the magma ocean haed creestallised, lawer-density plagioclase meenerals coud form an fleet intae a crust atap. The feenal liquids tae...