Bead blasting is the process of removing surface deposits by applying fine glass beads at a high pressure without damaging the surface.
It is used to clean calcium deposits from pool tiles or any other surfaces, remove embedded fungus, and brighten grout color. It is also used in auto body work to remove paint.
In removing paint for auto body work, bead blasting is preferred over sand blasting, as sand blasting tends to invite rust formation under re-painted surfaces. It's additionally used in cleaning mineral specimens, most of which have a Mohs hardness of 7 or less and would thus be damaged by sand.