Is this stone or poured concrete? If stone, what kind?

Poured stamped concrete

Only under extreme conditions should PROPERLY PREPARED concrete do this...notice the "properly prepared". I suggest you get the contractor back and ask.

That is not normal I would seek advice from another contractor.

Minor cracks along the joints are common, they called "shrinkage cracks" or they could be caused by pushing imprinting tools into the concrete after the surface became too hard. Also these cracks can occur during surface hardening on its own, some call that crusting and that can happen from the sun exposure, or it could be the concrete mix, etc. These small cracks can be easily repaired using matching color cement paste, if there is a bigger chunk broke off is can be fixed by using a color patch. Most Manufacturers make matching "color hardener" patches to fill and repair these types of cracks, I'm sure your contractor has them, most keep them in a variety of colors or get them as needed.

The area around the stoop was badly troweled and over finished and that is why you see discoloration and the flaking of the surface and it will only get worse with time, because when that happens it could weaken the top layer anywhere from 1/4 - 3/4" in some cases even more, causing surface failure. That should definitely be repaired.

If you used a licensed contractor and you have a contract with a provided warranty, you shouldn't have a problem rectifying this issues.

Best of luck

Thank you so much for your wise words. Legal action has started. Dad's Diversified has not responded in a timely matter. I've been dealing with this problem for 7 weeks too long.

Hi Theresa. Wondering what ended up happening with this? I’m in the same situation.