https://www.youtube.com/watch?v=UbvPhqSG5C4
by @AncientArchitects


@JorgeStolfi
1 month ago
Greek Fire is a fascinating subject, but I don't see the need to invoke it here.  While igneous rocks like granite and basalt may resist heat until 1000 C or more, other rocks can be damaged by ordinary wood fire.   For instance, sandstone (which seems to be the material of those statues) consists of sand grains glued together by clay- or limestone-like minerals.   When heated to a few hundred C, the sand grains (which melt only at 1700 C) will remain intact, but  the "glue" will partially break down and change color, so the rock will discolor and become weaker -- but without melting.
Also, whatever Greek Fire was, it probably did not burn much hotter than wood fire.  Apparently, it was effective only because it got spread all over the ship and crew, and (if that queen's recipe is any good) it stuck to whatever it hit, like napalm, instead of running off. 
Gunpowder may reach 1450 C while burning (M. E. Brown, R. A. Rugunanan, 1989), but only if it has the right composition, texture, humidity, packing, etc. And I suspect that the high temperature may be due to carbon, which AFAIK no one mentioned as ingredient of Greek Fire.  Even if the latter included saltpeter (sodium nitrate) it seems unlikely that it would reach 1000 C.  Especially when sprayed from a distance, instead of packed in a crucible.