It's what Fat said... a flint/chert nodule. (Flint is a variety of "unweathered" chert.) The exterior of your nodule is what geologists and rock-hounds call weathered, meaning, exposed to air and rainwater or groundwater, etc, for hundreds or thousands of years. To see more like it, google-search "Chert Nodule" and "Flint Nodule."
Yep but I’d bet money it’s been in a fire that’s what causes all those little cups I believe you’ve circled a crinoid or other remnant of a sea creature
I agree that it could have been in a fire. The surface craters look like fire pops and the fire could have heat treated some of the surface to a bluish color.