Definitely not as accessible for every day heating as wood but for something higher value like a blacksmith it might make sense to trade for it.

I think the bigger problem is the distribution of knowledge. Would French blacksmiths know of coal’s usefulness in the same century as it becomes widely used? Maybe in the printing press era, but it’s a bit of a stretch in the 13th century.

Charcoal is just as goodias coal in general. Depending onethe grade of coal it might even be better. Coal is less effort though as you dig it up in quanitiy as opposed to needing trees in the first place (these run out all the time) them the effort to cut and process them.

> Charcoal is just as goodias coal in general.

is an almost meaningless statement in the context of producing quality iron and steel.

"Charcoal" is a reasonably consistent product, "Coal" is an entire spectrum that ranges from [thermal coal] through to [metallurgical (coking) coal].

In a quality production pipeline there's a seperation between means of generating furnace heat (can be electric arc, can be thermal coal fired, can be charcoal) and a means of sourcing carbon for bonding with raw iron ores (coking coal).

In the context of low grade iron and poor steel manufacture the distinctions matter less.