what is this?

[Dyncaus]

does anyone know what this is or what it was... i was reaquascaping a couple days ago and while i was moving around the rock i noticed this stuff on it and decided to place it up against the new halides i got, its kind of honeycomb looking texture wise. thanks

[PeeJ]

looks like some kinda sponge to me

[Brett Wilson]

Looks a lot like porites from FIJI. very common to find this on fiji rock. I actually had some survive, it's the size of a baseball now.

[greatbarrier52]

I agree Brett