| Macphersonite | Pb4SO4(CO3)2(OH)2 |
| Magnesiochromite | (Mg,Cr,O) |
| Magnesite | MgCO3 |
| Magnetite | Fe3O4 |
| Malachite | Cu2(CO3)(OH)2 |
| Malladrite | (Na,Si,F) |
| Maldonite | Au2Bi |
| Manganite | MnO(OH) |
| Marcasite | FeS2 |
| Marshite | (Cu,I) |
| Maslovite | (Pt,Bi,Te) |
| Massicot | PbO |
| Matlockite | (Pb,F,Cl) |
| Mattagamite | (Co,Te) |
| Matildite | (Ag,Bi,S) |
| Maucherite | (Ni,As) |
| Mayingite | (Ir,Bi,Te) |
| Mcguinnessite | (Mg,Cu)2(CO3)(OH)2 |
| Melanophlogite | C2H17O5(SiO2)46 |
| Melanostibite | (Mn,Sb,O) |
| Melonite | (Ni,Te) |
| Mendipite | (Pb,Cl,O) |
| Meneghinite | Pb13Sb7S23 |
| Mercury | Hg |
| Metacinnabar | (Hg,S) |
| Miargyrite | AgSbS2 |
| Michenerite | (Pd,Pt,Bi,Te) |
| Microlite | (Ca,Na)2Ta2O6(O,OH,F) |
| Miersite | (Ag,Cu,I) |
| Millerite | NiS |
| Mimetite | Pb5(AsO4)3Cl |
| Minium | Pb3O4 |
| Minrecordite | CaZn(CO3)2 |
| Moissanite | SiC |
| Molybdenite | MoS2 |
| Monazite | (Ce,La,Th,Nd,Y)PO4 |
| Morganite | Be3Al2(SiO3)6 |
| Moschellandsbergite | Ag2Hg3Ca2(Mg,Fe)5Si8O22(OH)2 |