The minerals and deposits in stones can have organic qualities, which provide
the fungus spores with nutrients so it can establish itself.
The stone's surface pores provide excellent footholds for the spores and when they have gotten a hold, the affections keep returning until all spores and all remains of fungus have been removed.
Bensaltenside sterilizes the affections and growth by fungus and disinfects the stone surface. Current affections are killed within 24 hours and future growth becomes impossible.