Exploding Flint

At last something to do with those creations that don't quite turn out as you intended.

I wonder what the difference is between fire bar flint and raw flint,

I've often wondered that, running a bit of steel along a rounded bit of regular flint produces precious few sparks. Perhaps it's something in the steel.

I think the steel does have a lot to play in it but I wonder if any flint would light when struck with the correct steel.

I believe ist's nothing to do with it being flint, but hardness on the Mohs scale, so other rocks at least as tough as flints work fine. In Germany they have little flint, so made their gun flints from agate instead.