Draconis Fundamentum

Hi Everyone! I posted a few weeks ago about harvesting a dragon, and now I am back for more questions! I decided to include the Draconis Fundamentum as the dragon's magical source. It will be an option for the players to try to harvest. I do not have access to the dragonomicron so i don't know what the material says, but I want to make sure they know the potential uses of it (if they roll high enough to know.)

I've seen some things state it can be used as a kind of elemental bomb, while other state it can be like some sort of power source or magical focus. What i mean is, I have seen a lot of variation.

What have people allowed their players to use the Draconis Fundamentum for in their games?