"Ignite rock" isn't a recognized geological term. It's possible there's a misunderstanding or a different name for the rock you're referring to.

To help me understand what you're asking, could you please clarify:

* Do you have a picture or more specific description of the rock?

* What are the key characteristics of the rock? (e.g., color, texture, where it's found)

* What makes you think it's "ignite rock"?

Once I have more information, I can better assist you in understanding how the rock was formed.