Natural magnesium carbonate (magnesite); fused magnesia; deadburned (sintered) magnesia, whether or not containing small quantities of other oxides added before sintering; other magnesium oxide, whether or not pure
Natural magnesium carbonate "magnesite"
Fused magnesia; deadburned "sintered" magnesia, whether or not containing small quantities of other oxides added before sintering; other magnesium oxide (excl. natural magnesium carbonate "magnesite")