Need additional images of other sides and location data to determine if this a fossil and if so what.

Looks like fossilized coral that’s been naturally tumbled

looks like coral

Yep coral

Hi there @pat-hebert, for proper curation, each post should have only one specimen in the pictures! This does look like coral! Could you input the specific site locations of it, as that can help narrow down geochron and lithostrat for ID purposes!

They are corals and referred to as Petoskey Stones

Hi there! @pat-hebert, these do look like Petoskey Stones made from fossilized rugose coral (Hexagonaria percarinata). For all of your recent uploads, in order for a specimen to be properly curated each post must be for one individual specimen! That specimen can be photographed against a neutral background with a scale for reference.

Corals

Coral

Nice pieces of coral

Looks like limestone which is made of calcite. Calcite is soluble and dissolves in acid which is what the holes are suggesting. Try putting some weak acid on it to see if you get a reaction. Quartz is harder and not soluble and therefore will not react to acid.

coal