QAPF diagram (Petrology 💎)
A QAPF diagram is a doubled-triangle plot diagram used to classify intrusive igneous rocks based on their mineralogy. The acronym QAPF stands for "Quartz, Alkali feldspar, Plagioclase, Feldspathoid ", which are the four mineral groups used for classification in a QAPF diagram. The percentages of the Q, A, P and F groups are normalized, i.e., recalculated so that th...