Oh yes it is. I wonder who really is holding their hands over their ears (and eyes).
Abramelin posted several times about use of chemicals (oxalic acid in particular) on the stones. Now, use of certain plants altogether with the sand may make grinding easier, and producing, as you say, "vitrified" surface. Plausible? Guess so.
Shatters the fairy tale mainstream theories in a single stroke.
Makes my job much easier I suppose.