Plsss explain this diagram

Sajan sarthak

A QAPF diagram is a double ternary diagram which is used to classify igneous rocks based on mineralogic composition. The acronym QAPF stands for "Quartz, Alkali feldspar, Plagioclase, Feldspathoid (Foid)". These are the mineral groups used for classification in QAPF diagram. The QAPF diagram utilizes four minerals, or mineral groups, to classify igneous rocks. These minerals are quartz (Q), Alkali feldspars (A), plagioclase feldspars (P), and feldspathoids (F). F and Q cannot form in plutonic rocks simultaneously due to the difference in their respective silica contents. Other minerals may occur in samples, but they are not utilized by this classification method. The QAPF diagram is composed of two ternary plots (QAP and FAP) joined along one side. To use this classification method, the concentration (the mode) of these minerals must be determined and normalized to 100%. For example: a plutonic rock that contains no alkali feldspar and no feldspathoids, but contains many pyroxenes (unlabeled in QAPF diagram), plagioclase-feldspar, and few quartz grains is probably gabbro (located at the right edge of the diagram, near P). This diagram makes no distinction between rock types of the same chemical composition in QAPF, but different chemical compositions with respect to other minerals (such as gabbro, diorite, and anorthosite). Note that this diagram is not used for all plutonic rocks. Ultramafic rocks are the most important plutonic rocks that have separate classification diagrams.