It crystallizes as isolated silicate tetrahedra, making it especially susceptible to chemical weathering, and it crystallizes first in the discontinuous branch of Bowen's reaction series before pyroxene.
In the traditional picture of the 660-kilometer mantle discontinuity, the discontinuity is due to this mineral group's post-spinel phase transitions from ringwoodite to perovskite and magnesiowüstite. Dunite is primarily composed of this mineral group, which has endmembers fayalite and forsterite. It crystallizes as isolated silicate tetrahedra, making it especially susceptible to chemical weathering, and it crystallizes first in the discontinuous branch of Bowen's reaction series before pyroxene. Known in its gem form as peridot, FTP name this common mineral group of ultramafic rocks named for its green color.
In the traditional picture of the 660-kilometer mantle discontinuity, the discontinuity is due to this mineral group's post-spinel phase transitions from ringwoodite to perovskite and magnesiowüstite.
{olivine}