MINERALS MAGNESITE Magnesite is a compound of magnesium, its chemical formula is MgC03, and its color varies between white, yellow, grey and brown. It is found in nature as cryptocrystalline and crystalline. It is a tough and complex mineral, and is an alteration product of serpentinite or similar rock types. There are magnesite reserves in Konya, Balıkesir, Bursa, Bilecik, Ankara, Kütahya, Eskişehir and Erzincan.