- iron stain
- iron sulphide
- iron tourmaline
- iron tube
- iron work
- irreducible saturation
- irreversible colloid
- irruption
- isethonic
- isinglass
- island arc
- island chain
- island hill
- iso-curves
- isobar
- isobutane
- isobutene
- isobutylene
- isochrome
- isochronal annealing
- isochronous pendulum
- isocolloid
- isoconcentration
- isoconcentration map
- isocracking
- isocrotonic
- isocyanic
- isofacial
- isoforming
- isogeothermal
- isogonic chart
- isogonic map
- isolable
- isolation
- isolog
- isologue
- isomate
- isomeric change
- isomerization
- isometric latitude
- isometric system
- isomorph
- isomorphism
- isonomalic map
- isooctane
- isopach map
- isopentane
- isopentene
- isopical
- isopical deposit
- isopoly acid
- isoprene
- isopropanol
- isostasy
- isostatic adjustment
- isostatic anomaly
- isostatic compensation
- isostatic equilibrium
- isostatic reduction
- isostatical settling
- isosteric
- isosynthesis
- isothermal annealing
- isothermal quenching
- isothermal reaction
- isothermal test
- isotopic fuel
- isotopical deposit
- issue
- issue price
- itinerant worker
- ivory black
- ivory board
- jacinth
- jack latch
- jack shaft
- jagged rock
- jalap
- jamin effect
- jamming
- japan
- Japanese paper
- japanner
- jasmine oil
- jaw clutch
- jell
- jellification
- Jeremiassen crystallizer
- jet ejector
- jet perforator
- jitter
- jobber
- joint cement
- joint filler
- joint interest
- joint liability
- joint report
- Joint venture
- jointed
- jointing adhesive