GEOLOGY

Detailed explanation-1: -The olivine group (Mg, Fe)2SiO4, is a group of igneous minerals which is commonly abundant, and quickly weathered, on the Earth’s subsurface. Olivine is a mixture of magnesium-rich forsterite (Mg2SiO4) and iron-rich fayalite (Fe2SiO4). Forsterite is more common than fayalite (Klein and Hurlbut, 1993).

Detailed explanation-2: -ferromagnesian minerals: Olivine, Pyroxene, Amphibole, and Biotite, which are all dark, ferromagnesian minerals.

Detailed explanation-3: -Biotite mica can have iron and/or magnesium in it and that makes it a ferromagnesian silicate mineral (like olivine, pyroxene, and amphibole). Chlorite is another similar mineral that commonly includes magnesium.

Detailed explanation-4: -ferromagnesian minerals Silicate minerals in which cations of iron and magnesium form essential chemical components. The term is used to cover such minerals as the olivines, pyroxenes, amphiboles, and the micas biotite and phlogopite.