Gideon Singer wrote in message . ..
Thanks to all.

Just for the info of others CLR did not remove the rust from the
rocks. ....

Then the only alternative is to abrade the surface carefully to retain
the contours. --Don't- use a steel brush. There are various flexible
grinding discs out there. Try one on a rock and see what happens.
The surface should eventually weather to grey. You may have to remove
a good bit of rock if the stone is porous.

Wear good eye protection if you try this.


J. Del Col