What are these?

[Animal-Chin]

I have these all over the tank. They look like little sps coral that are small little cone shape things. If you touch them they retract the fuzzy polyps that cover it, just let ke an sps. They are pointy, almost shaped like a snail shell. I can lile 20 of them in various places in the tank. Thoughts?

 

[coralbandit]

Looks like pineapple sponge.
Safe.

 

[Animal-Chin]

Its hard like coral, are pinaapple sponges calcium based?