Fissures occur in larger numbers in most quartzite, compared with other stone types. It's a brittle and very hard stone. It tends to react with a bit of crystalline shattering or fissuring with impacts, including drilling. With a proper vacuum injection of epoxy, the slab isn't structurally compromised. That needs a better repair, and it will be much less visible, and not at all a structural issue.

Thank you! Are cracks and fissures the same thing? I was thinking that a fissure is naturally occurring while a crack is the result of improper handling. From what I've read elsewhere in this forum, you can feel cracks with fingernails, but cannot feel fissures.

"Are cracks and fissures the same thing?"

Yes. A "fissure" is the natural stone industry telling you there isn't anything wrong.

It wasn't the drilling that caused the cracks; it was the grinder slamming into the stone when the plug let go. Purely installer error. Rookie mistake.

He should have used some color matched Sharpie on the cracks before the epoxy; now the lines are probably permanent. There is no cosmetically acceptable "epoxy injection" for countertops; if you've got concrete with appearance that doesn't matter, inject away please. There is ultra thin super glue dribble and top pounding to coax the cyanurate into the crack after the crack is color matched with Sharpie.

Take a picture back farther please so we can see the sink, the countertop around it, and the drawer. It may be possible to cut in a new sink with a faucet deck. Now most of the crack will be cut away.

I would be very upset unless they are able to make the lines disappear.

I just want to say your stone is GORGEOUS! Would love to see a picture from further back

I'll bet he never took a diamond pad by hand to the lip of the hole, leaving stress risers in the stone which could start more cracks.

"Lenny Elbon, a research chemist for Fountainhead, explains that
solid surface, although made from polymer resins, is often labeled
as a ceramic-type material. “Other ceramic materials include glass
and natural stone,” he says. “These materials are very strong,
don’t stretch much under a load, and when they reach their yield
point, suffer catastrophic failure."

To check on moisture penetration, I left a wet rag on the area for about an hour, and can now see darkening where water seeped in along the large crack at one o'clock, as well as the smaller cracks at 6 and 10.

That's good news; it means the cracks aren't filled yet. After the water dries, rub a color matched Sharpie over the cracks using a paper towel to remove the excess, then dribble super glue into them. Tap on the top with the base of your fist to work it in. When it cures, scrape it flush. That's as good as you're going to get. You may be surprised.

Do this now before the cracks become contaminated please.

You have cracks running from a hole in the counter. Kind of like when a rock hits the windshield of your car. If it can be made invisible, great. If not, it's completely unacceptable.

Thanks for the tip, Joseph Corlett! I used a gray Sharpie and it really helped. You can still clearly see the crack, but at least this now looks more natural. (See before and after below) Still worried about longevity tho... will water and bacteria eventually penetrate? With this being so close to the sink, it's a frequently wet area. This is the longest crack. There are 3 more that are about 2 inches each between the holes.

"Still worried about longevity tho... will water and bacteria eventually penetrate?"

Overfill with ultra thin super glue and scrape to flush please. Wipe up spills right away. They'll probably eventurall fill with contamination.

Thank you JC. When you say "eventually fill with contamination" what does that look like?

The cracks turn dark.

Honestly, if you CAN, in spite of the hassle, get it replaced. When Joseph Corlett says installer error, it's installer error. It shouldn't be your job to fix it, especially if it's going to still look like someone drilled a hole wrong and broke the countertop.

Did fabricator drill the hole after the counter was installed? If not, he should have alerted you to the cracks before it was installed. At least at that point you could have said.."nope, take it away".

Quartzite is a difficult stone to cut. However, the fabricator should know that the correct blade and maybe a water application is necessary to make it work.

Sorry, and yes, the countertop should be replaced.