Stains on new granite benchtop

[charlieb]

I've just had a new granite kitchen benchtop installed a week ago. The workmanship is fine, but when it was being installed we noticed some strange shadows across the face of it (see attached photo). The installer wasn't too worried about it ... he just installed it and went on his merry way. Now that the benctop is in place, these "shadows" are now really obvious. They appear to be stains across the face of the stone, and definitely not the grain itself ... they look like something has been rested against the slab, sometime between when we chose the slab at the warehouse and when it was cut to size. Can't tell if it's moisture, or oil, or rust, or just plain dirt.
Has anyone out there got any ideas on "a" how to identify what it is, and "b" how I might get rid of it?
Image attached.
Thanks.

[Joe Little]

Looks like moisture in the stone, clean with acetone and let it dry. could take a week or more depending on the environment
and the amount of moisture in the stone.

Of course , this is a guess from looking at a picture

[GuyboR]

Looks like moisture in the stone, clean with acetone and let it dry. could take a week or more depending on the environment
and the amount of moisture in the stone.

Of course , this is a guess from looking at a picture

My guess also Joe.

What did your fabricator say about them?

[Jeff H.]

Looks like moisture to me also. What product did the installer use for setting the stone?

[charlieb]

Thanks for your feedback guys ... very helpful. I've tried several times to talk to the supplier/installer, but they're playing hard to get and are proving to be disinterested now that they've got my money. I will try acetone as you suggest, to see if that helps in any way.
At the end of the day I guess I could look at some kind of consumer legal action against them, but I'm sick of dealing with courts at my stage of life. I'd rather deal with the matter myself or give pretend the problem's not there and just live with it.
Thanks again.

[topshop]

but I'm sick of dealing with courts at my stage of life. I'd rather deal with the matter myself or give pretend the problem's not there and just live with it.

It is sad to say but there are too many disreputable contractors that make a living off that lack of persistence. Please don't let them get away with ignoring you.

You could try to mix diatomaceous earth or white flour with the acetone and apply it to the area. Cover it with saran wrap, tape off the edges, poke a few holes in the wrap and let it sit until it is completely dry (a few days usually). That should poultice out the moisture or oil from the stone without damaging the stone.

[Omicron Granite]

I second the recommendation of trying acetone. It's worked for me in the past in similar situations.

[Dan R.]

If you poke holes in the plastic the Acetone will evaporate through the plastic instead of penetrating the stone, rehydrating the tannish and then carrying them to the DE. It will be much more effective if you leave the plastic intact and force as much Acetone into the stone as possible.

Acetone is highly evaporative and will follow the path of least resistance. Through a hole in the plastic is far less resistance than being forced into the stone surface. NO HOLES!!!

[JMarcella]

Have the slabs or finished pieces ever been stored outdoors? Were the tops sealed? If so, what product did they use?
It looks like drip lines from water running between the slabs and possibly staining them. Hard to tell from the pic.

[Chris Mills]

If you poke holes in the plastic the Acetone will evaporate through the plastic instead of penetrating the stone, rehydrating the tannish and then carrying them to the DE. It will be much more effective if you leave the plastic intact and force as much Acetone into the stone as possible.

Acetone is highly evaporative and will follow the path of least resistance. Through a hole in the plastic is far less resistance than being forced into the stone surface. NO HOLES!!!

X2 NO HOLES!