U
U-bit
Udden grade scale
ugrandite
uhligite
uigite
uintaite
ulexite
ullmannite
Ullrich magnetic separators
ulmain
ulmification
ulmin brown
ulminite
ulrichite
ultimate analysis
ultimate bearing capacity
ultimate bearing pressure
ultimate CO (sub 2)
ultimate compressive strength
ultimate elongation
ultimately controlled variable
ultimate strength
ultimate tensile stress
ultrabasic
ultrabasite
ultraflotation
ultramafic
ultramafites
ultramarine
ultramarine yellow
ultrametamorphism
ultramicroscope
ultramylonite
ultrasima
ultrasonic drilling
ultrasonic inspection
ultrasonic testing
ultrasonic tests
ultrasonography
ultraviolet
ultraviolet rays
ultrawet
ulvite
ulvoespinel
umangite
umbauhobel
umber
umbrella
umohoite
umpire
U.M. plate
unakite
unbalanced cutter chain
unbalanced hoisting
unbalanced shothole
unchuck
unclassified excavation
unconfined compression appliance
unconfined compression test
unconfined compressive strength
unconformability
unconformable
unconformity
unconsolidated strata
unconsolidated surface deposits
unconventional mineral deposit
unctuous
uncut
undation theory
under
underboom sprays
underbreak
underbreaking
underburden
undercast
underchain haulage
underchaining
underclay
underclay limestone
undercliff
underconsolidated soil deposit
undercurrent
undercut
undercut atomizer
undercut ignition
undercut quarry
undercutter
undercutting
undercutting machine
undercutting of old workings
underdrilling
underearth
underedge stone
underfeed
underfeed stoker
underfire
underflow
underground bunker
underground cable
underground coal gasification
underground connections
underground dam
underground exploration
underground fires
underground garage
underground gasification
underground geology
underground glory-hole method
underground haulage
underground milling
underground mine conveyor
underground opening
underground ore bin
underground shaft
underground station
underground surveying
underground transformer
underground transportation
underground water
underground workshop
underhand longwall
underhand stope
underhand stoping
underhand vertical slice
underhand work
underhole
underlay
underlay shaft
underlevel
underlie
underloading
underlying
underlying beds
undermanager
undermine
underpinning
underpoled copper
underream
underreamer
underreamer bit
underreamer cutter
underreamer lug
underreaming
underreaming bit
underrope haulage
undersaturated
underscreen water
undersea prospecting
undersea workings
undershot wheel
undersize
undersize control screen
undersize core
underthrust
undertow
undertub system
undervoltage relays
underweight
underwinding
undeveloped land
undiscovered resources
undisturbed sample
undulatory extinction
unequal angle
uneven fracture
unfaced quartz
ungemachite
ungotten
uniaxial
uniaxial stone
unicline
unidimensional consolidation
unidirectional ventilation
uniformitarianism
uniformity coefficient
Unifrax
unilateral transducer
un-ionized
union shop
unique diameter
unit
unit cell
unit coal
united veins
unit operation
unit pressures
unit process
unit retardation plate
unit strain
unit stress
unit train
unit value
unit ventilation
unit weight
unit weight of water
univalent
universal arc-shearing machine
universal clamp
universal coal cutter
universal coupling
universal gas mask
universal-joint couplings
universal lay rope
universal machine
universal motor
universal pH indicator
universal plant indicator
universal stage
universal testing machine
universal train
unkeying
unlimited pump
unloader
unloading conveyor
unloading trough
unlocking
unmix
unmixing
unoriented
unpatented claim
unproductive development
unproven area
unreserved mineral
unrestrained compression apparatus
unripe diamond
unsaturated
unscreened coal
unsealing
unsoiling
unsoundness
unstable
unstable isotope
unstable relict
unstratified
unwatering
unweathered
upcast
upcast shaft
upconing
upgrade
upgrading
uphill shaker conveyor
up hole
uphole shooting
uphole time
uplift
up-over
upper
Upper Barren Coal Measures
upper break
upper explosive limit of flammability
Upper Productive Coal Measures
upraise
upright
upright fold
upright joints
upset
upsetting
uptake
upthrow
upward-current washer
uraconite
uralborite
Uralian emerald
uralite
uralitization
uramphite
uran
urania ceramics
uranian opal
uranic ocher
uraninite
uranite
uranium
uranium borides
uranium disintegration series
uranium galena
uranium-lead
uranium minerals
uranium oxide
uranium trioxide
uranmica
urano-
uranocircite
uranolite
uranophane
uranopilite
uranorthorite
uranosphaerite
uranotantalite
uranothallite
uranothorianite
uranothorite
uranotile
uranphyllite
uranpyrochlore
urao
urea
Ure's process
Urgonian
urnel
urolith
urtite
Uruguay amethyst
usable diamond
usable iron ore
usables
usable stone
used bit
useful area
useful pressure
Usspurwies arch
U-stage
ustarasite
usual mining privileges
utahite
utahlite
U-tube manometer
uvanite
uvarovite
uvite
uwarowit
uzbekite