When tiling around a working fireplace, are special tiles, adhesives and/or grout needed?

I suppose it depends on how the fireplace is used - dog grate, gas fire, wood burner, etc - all have different heat outputs, and some will get the base VERY hot.

UFH is only luke warm by comparison.  I suppose fire cement wouldnt work?

My woodburner sits on york slabs, on soil with lime mortar.   I have a fireplace with terracotta tiles but Im not sure what they are bedded on - it has a slightly plasticy look to it.

Make sure it all has plenty of time to set before they use it.

Re - your other question, I think you do need a wet diamond cutter for decent results.   Someone asked about travertine before and got a full answer with lots of info about sealing.

I do know that some fireplace places wont supply a single piece of marble for a hearth because it tends to crack.   They do three pieces - one for the back under the fire/stove, then two seperate bits for the front, a left and right half.