Q. I think the cleaning company spilled toilet bowl cleaner on my black granite floor and it left a stain.  What do I do?

A. There are several possibilities. One, it is possible that you have a stone that has been 'doctored.' Some less than reputable distributors sell gray granite that has been altered to make it appear to be black granite. The problem is that the substance used does not hold up and eventually you have 'black granite' with grey spots. If this is the case, the darkening substance may have been removed by the cleaning agent.

Two, if your stone was sealed and all the sealer was not removed from the surface, damage to the sealer (rather than the stone itself) has been etched.

The third, and the most likely answer, is that there was hydrochloric acid in the cleaning agent that was spilled and no stone can hold up to that.

You could try an enhancer to mask the problem, but it probably would not look uniform. Your very best bet is to contact a restoration contractor and have them restore the floor. If you need a PRO, contact us.