| 0 | MACPHERSONITE (Lead Sulfate Carbonate Hydroxide) |
| MAGNESITE (Magnesium Carbonate) | |
| MAGNETITE (Iron Oxide) | |
| MALACHITE (Hydrated Copper Carbonate) | |
| MANGANBABINGTONITE (Calcium Manganese Iron Silicate Hydroxide) | |
| 0 | MANGANESE (Mn) |
| MANGANITE (Manganese Oxide Hydroxide) | |
| 0 | MARBLE (a metamorphic rock from limestone) |
| * | MARCASITE (Group) |
| MARCASITE (Iron Sulfide) | |
| MASSICOT (Lead Oxide) | |
| MELANITE (the black variety of Andradite Garnet) | |
| MELANOPHLOGITE (Silicon Oxide with organic compounds) | |
| 0 | MELANTERITE (Hydrated Iron Sulfate) |
| MENEGHINITE (Lead Antimony Sulfide) | |
| MERCURY (Hg) | |
| MESOLITE (Hydrated Sodium Calcium Aluminum Silicate) | |
| 0 | META-ANKOLEITE (Hydrated Potassium Uranyl Phosphate) |
| META-AUTUNITE (Hydrated Calcium Uranyl Phosphate) | |
| META-TORBERNITE (Hydrated Copper Uranyl Phosphate) | |
| META-URANOCIRCITE (Hydrated Barium Uranyl Phosphate) | |
| META-VARISCITE (Hydrated Aluminum Phosphate) | |
| META-ZEUNERITE (Hydrated Copper Uranyl Arsenate) | |
| 0 | METAMORPHIC (rocks formed via heat and pressure) |
| 0 | METEORITES (primordial rocks that fell to Earth) |
| MIARGYRITE (Silver Antimony Sulfide) | |
| * | MICA (Group) |
| MICROCLINE (Potasium Aluminum Silicate) | |
| MICROLITE (Calcium Sodium Tantalum Oxide Hydroxide Fluoride) | |
| MILARITE (Hydrated Potassium Calcium Aluminum Beryllium Silicate) | |
| 0 | MILKY_QUARTZ (variety of Quartz) |
| MILLERITE (Nickel Sulfide) | |
| MIMETITE (Lead Chloroarsenate) | |
| 0 | MINASGERAISITE - (Y) (Calcium Yttrium Beryllium Silicate) |
| * | MINERALOIDS (Class) |
| MINIUM (Lead Oxide) | |
| MIXITE (Hydrated Bismuth Copper Arsenate Hydroxide) | |
| 0 | MOCTEZUMITE (Lead Uranyl Tellurite) |
| MOISSANITE (Silicon Carbide) | |
| 0 | MOLDAVITE (variety of Tecktite: Meteoric Silica Glass) |
| 0 | |
| MOLYBDENITE (Molybdenum Sulfide) | |
| MONAZITE (Cerium Lanthanum Thorium Neodymium Yttrium Phosphate) | |
| MONTEBRASITE (Lithium Sodium Aluminum Phosphate Hydroxide Fluoride) | |
| MONTMORILLONITE (Hydrated Sodium Calcium Aluminum Magnesium Silicate Hydroxide) | |
| 0 | MOONSTONE (variety of Oligoclase, Sodium Calcium Aluminum Silicate) |
| MORDENITE (Hydrated Calcium Sodium Potassium Aluminum Silicate) | |
| MORGANITE (variety of Beryl, Berylium Aluminum Silicate) | |
| 0 | MOSCHELLANDSBERGITE (Silver Mercury or Silver Amalgam) |
| MOTTRAMITE (Lead Copper Vanadate Hydroxide) | |
| MURMANITE (Hydrated Sodium Titanium Niobium Silicate) | |
| MUSCOVITE (Potassium Aluminum Silicate Hydroxide Fluoride) |