At first glance without reading your post I'd think it's just the characteristics of the stone, and not a crack.

Does your fingernail snag on the top counter surface, sink cutout area, or both? If it's just the sink cutout area then I wouldn't worry.

I have granite and right after the install I noticed a small crack and even a small hole in the area where the sink is cut out and I FREAKED... well it's been over 6 years and the crack/hole area in the sink cutout looks exactly the same as day one. I don't worry anymore.

Pretty choice by the way :)

I am sorry this happened. Thank you for posting this, I am following this thread so I can learn more about FB... But just to clarify is Fantasy Brown a granite or a quartzite or maybe it's a marble? Not that it matters for your situation, I am just learning as I happen to the love the stone and going to a slab yard next week to re-think my counter options.

Fingers crossed it all gets fixed or replaced so that your counter is beautiful.

You've got to vibrate some very thin adhesive into the crack before it gets contaminated. I've beaten off hundreds of sinks and never cracked 3cm. See if there is a mechanical fastener right below the crack, please.

These are fissures, use something like tenax pectro

Thank you @ Javiva. I am learning so much on here. I appreciate the direction.

I have one of those exact cracks/fissures at the exact same place as you do. I put some superglue in it (followed Joe's directions) and it's totally fine after 4 years.

Thanks All! We really appreciate the input. We've never been in a position to install a natural surface and, unfortunately, the information we keep receiving is so contradictory it's maddening. Here (at houzz) no one has investment in our situation, so I'm weighing the input with more weight than the local input. The general consensus on here seems to point to "don't worry about it. Have them seal it (CA-SuperGlue) and move on". That is very relieving to hear, so thank you. As stated, this is a whole new world to us and we never imagined it to be so....daunting? :-)

That said, the installer/fabricator is going to be here this afternoon. I am hoping they do not try to spread flagrant BS and are honest with us.

@Javiwa - Thank you for that link, it was very informative. Unfortunately, I wasn't very happy with the part that discussed FB. Had we known about the Marble properties, we would never have selected it for kitchen countertops. All pre-sales talk and labeling referred to this as Granite and/or Quartzite. The final invoice calls it Marble. So I guess we treat it as Marble from here on out to stay on the safe side.

@chicagopa - Can you feel your crack/fissure with your fingernail on the face of the cutout?

@Featherbee - Yes, we can feel it with a fingernail on the cutout surface. We can NOT feel it on the counter surface.

@Joseph Corlett - Directly underneath the crack is a block of cabinet top the countertop rests on. In front of that, there is nothing, that space is open along the back the depth of the hole for the faucet. The sink is pretty much only supported where it is attached to the countertop with silicon adhesive.

Trying to determine what this is, Granite, Quartzite or Marble... Used a kitchen knife on the plug drilled for the faucet. a "light scratch" is an ambiguous statement, but this does not seem "light" to me, so am I safe to assume Marble based on image below?

I believe having the sink only supported by the silicone caulk is not good, but hopefully someone who knows his stuff will chime in on this. Our sink is supported by a Sink Setter which is metal brackets that mount to the cabinet. There are a number of different devices that do the same thing. The silicone is to seal the gap between the stone and the substrate.

If the sink is installed only with silicone it will come crashing down, only a matter of when. HUSH or a Sink Strap is the way to go.

And yes, that scratch proves it is marble.

" The sink is pretty much only supported where it is attached to the countertop with silicon adhesive."

That sink is coming down. Not "if", "when". I promise. Silicone has adhesive properties, but its function here is that of a gasket only.

Sinks must be mechanically fastened, preferably strapped.

If a knife scratched the stone and left an honest to goodness scratch (that won't rub out) then yes, it's marble - not quartzite.