Blemishes on Granite Countertops

What seems like a mar or mark might be the natural look of stone, or it could be residue from a spill. In any case, granite is hard to touch up. October 2, 2005

My company has recently contracted a granite shop to install a top for us. Now that the homeowners are moved in, they have noticed a small blurry spot on the granite. I contacted the granite guys, and they said they would not come out to fix this. So my question is this, what product should I use to try to remove this spot? Should I buff it out with a variable speed polisher? And what type of polishing compound should be used to get a real nice finish?

Forum Responses
(Laminate and Solid Surfacing Forum)
From contributor M:
I would suggest that you do not attempt to fix this. The small blurry spot is most likely a mineral deposit of quartz or something. You cannot polish a spot in granite, each mineral in the stone that makes up the whole polishes at a different pressure and heat rate. It takes a big machine that works the entire surface at the same time. If you attempt you will only further dull the area around the spot when compared to the entire surface. That spot is just part of the beauty of the real thing.

From contributor S:
What happens when there are stains or blemishes in Granite? Does the customer just accept it or is there a way to help them?

From the original questioner:
I am wondering the same thing. Do I just tell my customer to accept it? The granite company has told us no way they coming out to fix anything, so basically they left us out in the cold. My partner has already paid them in full, so not giving them their money, and getting another company is not an option at this point. Is there anything at all that can be done with it to make this spot look any better? Or should I just tell them thats a good place to keep a cutting board.

From contributor M:
There is no such thing as a stain or blemish in stone, it was created by nature therefore it is as it is supposed to be. When you polish a slab of stone, it is how it came out of the ground, only glossy. As for the quality of seams and etc, yes they should do better, stone is hard to work with but there are tricks to good seams and etc. Installers are key in this area.

From the original questioner:
Well I finally got to go by the house and see this blur for myself. I would say it is more like something happened when they where polishing the top. It is on the surface of the top, you can feel it. It is slightly rough to the touch, and is dull looking there. Just looking at it, it looks like paint over-spray, but it is not. So again I ask if there is anything I can do about this? Or would you still say it is a natural mark in the stone. (I know it is hard to be very specific when you have not seen it, but an educated guess would at least be appreciated).

From contributor P:
To the original questioner: Is the spot by a seam or in the middle of the top? If it is by a seam the installers may not have cleaned the seam completely; a couple of swipes with a rag soaked with acetone will clean the area. Look at a low angle to determine if the blurry spot may be residual epoxy from the seam. If the blurry area is in an isolated spot, this is a bit more suspicious. Granite is an incredibly hard stone closely rated to diamonds (on the rockwell scale), so the probability of a scratch or stain seems rather unlikely. It is not uncommon for slabs to have bruises in the material and sometimes the fabricator has to include this in the finished top. If it is a bruise you (or your local fabricator) should be able to buff it out. If it is a light scratch, you may be able to buff it out with progressive sanding.

From contributor W:
My hunch is that your fabricator tried to sand/polish the material for some reason. Its most likely a scratch. It is very rare to have a significantly dull spot on a slab. If you found a very good installer or fabricator they may be able to polish it and make it look better, but the second you touch the surface with polish pads, you can pretty much guarantee that it will never look the same again. A good fabricator though could get it to be pretty close.

From contributor G:
We are a cabinet/solid surface shop that started fabricating stone about two years ago. A dull spot should not come with the stone from the distributor. If it did, the fabricator did a poor job of inspecting prior to accepting the slab.

There are multiple reasons that this dull spot may be there. It has been pointed out that it very well could be some left over epoxy from seaming. Acetone is a good way to try and remove it. Another would be a razor blade. Scrape the top holding it perpendicular to the top. If it's epoxy, it should scrape it off.

Another possibility is the fabricator may have set something on the top at the shop. Does this dull spot seem to be about the size of a quart can? It may be epoxy from his can from the shop. If it is then use the same remedy as above.

Does the spot also feel pitted? If so, it may have to be etched. This happens when acid from certain products are left on tops. Oranges and lemons are highly likely to do such. That is why you seal certain granites and clean up spills quickly.

The dull spot (as noted above also) could be from where the fabricator tried to top-polish the slab to fix a possible scratch or defect. This is not as easy of a fix. This would need to be fixed by correctly top-polishing the slab. As stated above, it is difficult, but not impossible.

From contributor G:
I forgot to ask - what is the color of the stone?

From the original questioner:
The color is uba tuba. Black is what I would call it. And the spot is about 3-4 inches long and about 1 1/2 inches wide.

From contributor E:
What I would suggest is to either leave it alone or live with it, or you could try to polish it down with steel wool and also apply ager to it on the last application and rebuff with steel wool. It takes awhile but Ive had success with it and especially on uba tuba it should do fine.

The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor R:
I have seen spots like this on granite pieces. If it is not uniform around the edges, then it's probably a natural "defect" in the stone. Since this is naturally occurring in the stone, there is not much you can do about polishing the spot. You can try to re-source the granite and replace it, but I don't know of any company that will replace it for free, since it is a naturally occurring spot in the rock itself.

Comment from contributor J:
In regards to the original comment about the spot in the top, it is probably there forever. I have been a fabricator for over 14 years and now own a wholesale slab distribution company. Most slabs these days are imported resin coated to protect the stone. Most of the time, fabricators have managed to scratch the resin coat - not the stone, and this is almost impossible to repair. It sounds like this is what happened and they tried to fix it by polishing it out, but have compounded the problem.

Once a top is scratched, the best thing to do is leave it alone because you can't polish out the resin coat. Slabs come in from the quarry resin coated and free of imperfections 99.9% of the time with a glass finish. Without seeing this problem, I would say the only fix to this is to live with it or have the top torn out and replaced with new piece. But of course the new stone won't match because it will now come from a different bundle as stone is cut by book-matching slabs so that they match in color and grain of the stone.