- lutein
- luteocobaltic
- luteol
- lutetian stage
- lutidine
- lutidinic
- lutidone
- lye
- lyophobic
- lyosol
- macawood
- maceration
- macgovernite
- machinability rate
- machinable
- machine mining
- machine steel
- maclose rock
- macrocrystalline
- macrocyclic
- macroseismic
- macrospore
- madupite
- magmatic assimilation
- magmatic column
- magmatic segregation
- magnesia
- magnesian
- magnesian chalk
- magnesiochromite
- magneson
- magnetic chart
- magnetic clutch
- magnetic compass
- magnetic differentiation
- magnetic filter
- magnetic method
- magnetic north
- magnetic ore
- magnetic perturbation
- magnetic pyrite
- magnetic separation
- magnetic survey
- magnetic valve
- magnetite
- magnetometric surveying
- magnifying glass
- magnoferrite
- magnophyric
- mahogany
- maidenhair
- main bottom
- main crack
- main indicator
- main jet
- main land
- main lead
- main sea
- mainland
- maintenance crew
- lyonic
- lyophilization
- macadam aggregate
- Macassar oil
- macedonite
- machinability
- machinability index
- macroclastic
- macrofossil
- macromeritic structure
- macromolecular
- maculose structure
- madder
- madder lake
- madeirite
- maenaite
- mafic mineral
- magallarite
- magma chamber
- magmatic differentiation
- magmatic water
- magmatogene
- magnesia binder
- magnesia brick
- magnesian limestone
- magnesioludwigite
- magnesium test
- magnetic balance
- magnetic change
- magnetic dial
- magnetic pumping
- magnetometer survey
- main bearing
- main distribution
- main product
- make through
- makeup water
- making practice
- maldonite
- male cone