Monticellite
Monticellite and kirschsteinite are gray silicate minerals of the olivine group with compositions CaMgSiO4 and CaFeSiO4, respectively. Most monticellites have the pure magnesium end-member composition but rare ferroan monticellites and magnesio-kirschsteinite are found with between 30 and 75 mol.% of the iron end member. Pure kirschsteinite is only found in synthetic systems. Monticellite is named after Teodoro Monticelli Italian mineralogist (1759–1845).