I have recently moved into a house with a tiled kitchen floor and left some plant pots on cardboard on it. This got damp and has caused some brown rings and patches on the tiles where it looks like the colour and surface has been taken off. The rest of the flooring has a shiny coating on it. I have tried to find out exactly what the tiles are, but have only been able to confirm that they are natural stone. I have attached some pictures of the stains, could anybody give me some advice as to how to remove these without damaging the tiles or the coating? Many thanks