Grinding on a butt joint floor can be challenging, as mentioned on pervious email depending if the stone is set on concrete or wood. Hopefully if it’s set on wood there is still the setting material that would trap the moisture if aany waters penetrated through the joints. Usually floor that are but jointed still have been grouted. You just are not seeing the grout as well as you would if there was an actual grout line. If you grind this floor, I would recommend grinding it using minimum water or if you have dry grinding equipment then dry grind it, unless you have the proper dry vac and you are vacuuming as you grind you will have another problem DUST CONTROL .
I would grind it wet just control the amount of water used.
John E. Freitag
The Stone and Tile School
I have been question on grinding a limestone floor. The design of the tile is such that it is set butt joint and thus has no grout. If one was to grind the floor flat would there be a problem with water seeping below the tiles and possible causing problems. Appreciate your feedback.