Before grout... see the mirror-like sparkle?

After grout and much scrubbing :(

This section is half grouted and half ungrouted so you can see how dull it is.

There are acid cleaners you can use. I'm sure someone here knows but you can also check over at John Bridge Tile Forum. I think they say start with a mild vinegar. Forget if it's straight up or diluted. (applicable only to other stones and tile)

Did you seal the onyx first? Doesn't that have little cracks in it, that is, some porous areas?

This post was edited by snookums2 on Fri, Apr 19, 13 at 20:49

DO NOT use an acid based cleaner!! you will etch the hell out of it and it will be even worse!!!!

Yes, check with a professional first before doing anything! I was just trying to offer some initial reassurance.

You might have to resort to having it polished again.

This post was edited by snookums2 on Fri, Apr 19, 13 at 20:55

Thanks for your help. I went over to that forum you mentioned and it looks like they recommend using diluted white vinegar and a gentle scrubbing pad. I tried it and it worked! The sparkle is back. :) happy here!!!