Not meaning to cause a row but what are those stones they use on gas fires, the flames are curling round them all the time?
most often they are not stones but composite ceramics.
i notice even Sauna stones are now man made ceramic.
even when they weren't, they were "specific" types of rock. not something picked up from the river.
stones with a high metal content, do fair well when heated.
but a fracture, caused by an impact, will still allow them to go BANG, just the same.
here its not so much, can some rocks be heated.
its more down to do we really know which rocks we have.
if we suggest boiling, and the member makes the wrong choice of rock, and it explodes.
who would you blame?
the law may well blame the member who offered the suggestion, and through that, this forum.
i wish i still had the pressure cooker in which a lovely bit of sea washed blue slate exploded. (though i was not using the pressure function)
it was like a wall when Wile e Coyote has run into it. a perfectly formed image of the bits that hit the sides.
and i still have a few, faded scares from rocks going pop, whilst camping as a kid.
