Fossilised coral?

[Nav]

Hey all, found these whilst out fishing in the central west (NSW) and wondering if people thought they could potentially be fossilised coral? If not, any suggestions on what they could be?

Appreciate any thoughts.

Cheers,
Nik

 

[grubstake]

They look like pumice to me. Do they float?

 

[Nav]

They look like pumice to me. Do they float?

No, they’re very solid, hard as a rock abs sink pretty quickly