<Snipped quote by Mihndar>Pardon me Voltus but I don't think the energ content of Fyrurock was ever the point of that material.
What is the energy output of Fyrurock? Joules per cm^3 or grams.
It seems to be highly compressible which makes it easier to carry in large amounts while the incrediary vapors are good for flamethrowers and fuel air bombs.
https://en.wikipedia.org/wiki/Thermobaric_weapon
These
They're rather potent at destroying buildings because unlike explosions fuel air explosives are like a myriad of mini-explosions spread in a cloud within which they do relatively even damage.
The vapor can also slip through small openings thus for example cause some of the fuel to detonate inside the bunker.
Their longer detonation time also means they strain structures for longer than a regular explosive does.
Basically they are decent bombs. They aren't that notably stronger than regular explosives but their properties make them worthwhile for demolition.