zircon is ubiquitous in the crust of Earth. it occurs as a common accessory mineral in igneous rocks (as primary crystallization products), in metamorphic rocks and as detrital grains in sedimentary rocks. Large zircon crystals are rare.. Their average size in granite rocks is about 0.10.3 mm, but they can also grow to sizes of several centimeters, especially in mafic pegmatites and carbonatites.
