Gabbro Rock | Formation, Properties, Composition, Uses
QAPF modal classification of plutonic rocks (based on Streckeisen, 1976, Fig. 1a). Diorite, gabbro, anorthosite — the three root names in this field are separated according to the colour index and the average composition of their plagioclase – anorthosite (M < 10%), diorite (M > 10%, plagioclase An0 – An50), gabbro (M > 10%, plagioclase An50 –An100).