@Durin, for a technology idea, I'd like to suggest some kind of fuel or chemical that sets rockcrete on fire. Maybe by igniting the
synthetic binding agent that holds the rock and stone together.
Theres a RL chemical that as far as anyone can tell, can burn pretty much anything....
asbestos...you know, that stuff they use to STOP fires.
water...cas...yeah.....(it actually explodes on contact with water)
sand, glass, gold, platinum....the ash left over by "normal" fires.
nothing...because it will combust with itself.
Oxygen...yeah..thats right, it does to oxygen what oxygen does to wood....which means one could say that this stuff is so violent that it can even set FIRE on fire.....
as a bonus, it will do all this with no spark or prompting from external flame...its like nitroglycerin except made of fire instead of being explode-y
the best known way to store it is a special coating made of steel. technically that steel is not what does it, but rather what forms after reacting with the chlorine_trifuoride to from a metal Florine that won't explode...but don't let it get scratched as thats when the fire starts.....
wiki even says quotes somebody saying that the way to deal with a open fire of this stuff is "a good pair of running shoes"
this is because this stuff doesnt need fuel to burn, nor oxygen...and burns hot enough that the only way to forcibly put it out is with a flood of liquid nitrogen.....which will eventually warm up anyway and thus only slows the stuff down since its self-starting.
Chlorine trifluoride - Wikipedia
(yes, thats THREE fluorine atoms forced to bond with chlorine....)
phosphorus is called the devils chemical (or something like that)....this stuff is far, FAR worse.
This stuff reacts with your body to form
hydrofluoric acid and
hydrochloric acid, which are both dangerous acids Furthermore, due to this stuff's explosive quality in regards to water (which you are mostly made of) means that it will turn your body into acid and then explode said acid everywhere.