Crystal settling is the settling down of crystals in the magma in which they formed due to gravity. When crystals are newly formed in magma, they settle, leaving space for more crystals to form. As the non-silica content in magma decreases, magma will stop cooling into olivine and start producing pyroxene. The pyroxene also settles in magma. When crystals form in magma, they settle if they are denser than the magma, which they are most of the time.