Is it on the bottom of the piece as well? From the side view especially, it looks like the piece has been cut and glued back together, with a very poorly matched adhesive.

You can paint that thin line.

I was wondering if it was glued together! It's too heavy for me to lift but I will check that out when I have some help. What would you paint it with? I didn't know that was possible. Thanks for responding!

I was able to add a picture of the underside of the stone and yep the line is there as well. Looking like this was glued together. Highly disappointing as we purposely tried to find a piece that would span the length.

That's certainly a puzzler, but the line coming through on the back is evidence that the contamination goes all the way through. That's not good. You may have to learn to live with it. I'd try a couple drops of oven cleaner in an inconspicuous spot.

Since it seems it isn't installed yet, the entire back is inconspicuous, which is handy.

I went back to the fabricator today and showed them the pictures. They are looking into something that can be done. They said they want me to be happy with it so hopefully they can do something to make it look better. Thanks for all of the advice!

Glaxs Glue For Stone Possibly this could be used.

I find it odd that there are also lines that look like slices near it and that the pattern/movement doesn't match up, like it is a bunch of scrap pieces fused together. Is this actually quartzite or quartz?

You're right, Nova - now that you bring it up, I see a diagonal line in the first photo that looks like a seam, and another one perpendicular to that in the third photo. Those seam are very well done, but if not for the huge black line drawing attention, the breaks in the veining would be obvious.

If the fabricator really wants you to be happy, they will find you a remnant that's a whole piece!

This is quartzite or so they told me. We have alot of quartz in other areas of the house and the remnant does look like some sort of natural stone. The more I look at this the more I see what Nova is talking about - many areas where the pattern doesn't quite match up. The shop called me today and after the lead fabricator looked at the pictures they are sticking to the story that the line is part of the natural stone and not glued together. ugh. He did say if I wanted to pick something else out they would cover the remnant and give me some discount on re-fabrication. He does't think re-polishing will do anything so I may do that but don't really want to work with them anymore. The bummer is I also used part of that remnant for a powder room vanity sink they already started fabricating. He assured me that there are no black or blue lines in that piece and there's not much counter space so I'm hoping it will be ok. Lesson learned - one must inspect things with a fine tooth comb! The remnants were outside in the sun so I didn't pick up on it - even with pictures I took initially. I haven't tried the oven cleaner yet but anything is worth a try at this point. Thanks for all the input!

That is a natural fault brechia line. Just like an earthquake fault line, on a micro scale. The sand was separate waves of linear sections with mineral inclusions. Then it was compressed under the earth’s pressure and turned into sandstone. Then the plates moved, the sandstone fractured a bit in a series, was abducted under the earth, with heat and pressure, and it turned into quartzite.