The best replacement for iolite is mflb.

The best alternatives to iolite are rated as following:
★★★★★  mflb
★★★★  tanzanite
★★★  magic flight
★★★  no2
★★★  pax
★★★  launch box
★★  vapir
★★  davinci
★★  amethyst
★★  wispr 2
★★  arizer solo
★  wispr
★  magic flight launch box
★  vaporgenie
★  puffit
★  vapir no2
  blue sapphire
  atmos raw

Your alternative for iolite is not listed? Suggest!
Speaking about iolite, one probably shouldn't forget about sunstone.

Other search terms related to iolite and their ratings are:
★★★★★ sunstone
You have in mind a companion for iolite and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of iolite in all years. Click on graph for more.
iolite
mflb
tanzanite