This a 100% procedural ceramic material.
It features non regular tile placing as in reality : each tile is randomly shifted and rotated. The plaster joint thickness is also fluctuating and is realistically "flood-filling" the space between the plates.
This is a 100% bump material. Download the displacement version if you want proper closeups
Small tutorial to customize the shader, with a template version attached:
UV Coordinates : 1x1 square is one plate
Best suited for 10cm x 10cm plates
Tile generator shader v1