[carolynchr]

Our fireplace has a black concrete hearth. There are several white water stains on it that we would like to remove or cover. There is also a set of small dark hand prints on it. What can we do to restore the hearth to solid black? The home was constructed in 2007.

[tickle]

Was this a specially treated concrete, say concrete stained to look like black marble ?

[carolynchr]

There is no special effect--marble or otherwise. It is solid black. We don't know the contractor so don't know what kind of sealer was applied, if any.

[ballengerb1]

Try wiping it it down with white vinegar. This is a very mild acid and you can work your way up to dilute Mureatic acid if you use gloves and ventilation.