Remember: Forsterite = \(\text{Mg}_2\text{SiO}_4\), and Fayalite = \(\text{Fe}_2\text{SiO}_4\). Both belong to the olivine family but differ in their metal content.
Forsterite is a naturally occurring mineral that belongs to the olivine group.
It has the chemical formula \(\text{Mg}_2\text{SiO}_4\), which clearly indicates that it is a magnesium silicate.
It is often found in mafic and ultramafic igneous rocks and is a significant source of magnesium.
Hence, Forsterite is a mineral of magnesium (Mg).