- return airduct
- return stroke
- reverse dip
- reverse emulsion
- reverse osmosis
- reversed magnetization
- revolving screen
- rewored fossil
- Reynolds analogy
- rhabdophanite
- rhamnite
- rhigolene
- rhinestone
- rhodizite
- rhodusite
- ribbed cylinder
- ribbed plate
- rice oil
- rich coal
- rich ore
- rift valley
- rig down
- rig floor
- rig operation
- rig power
- rig up
- rigging down
- rigging up
- rigid plastic
- reverse speed
- reverse winch
- reversing valve
- reversion
- revival
- rhamnetin
- rhamnose
- rhodium
- rhomb spar
- rhums
- rice coal
- rich clay
- riddle
- ring structure
- ring-oiled
- ring-shaped
- rinjection
- ripple tray
- riser
- riser head
- rising pouring
- rive dog
- river cross
- river drift
- river head
- river placer
- river wash
- riverain
- rivet head
- retest
- rethread
- reticulated vein
- retinasphalt
- retort carbon
- retort gas
- retrograde
- retrograde condensation
- retrograde metamorphism
- return shaft
- reussinite
- reversed trace
- reversing arrangement
- reversing tool
- revive
- Rhaetian stage
- rheological variable
- rhodotilite
- rhombohedral system
- rhythmic bedding
- ribbed
- rich soil
- richter scale
- residual saturation
- residual soil
- residuary
- residue
- residue gas
- residuum grease
- resin cement
- resin putty
- resin soap
- resin-like
- resinite
- resinox
- resist
- resist coating
- resole
- resorcylic
- retigen
- retinellite
- retort