Yikes. Did you ask the fabricator?

I suspect capillary action between the sink flange and the stone bottom. Another quartzite nightmare added to the large stack here on Houzz.

The undercoating was filled with water from the faucet and disposal button not being adequately sealed. And the seam had a gap also. They pulled faucet etc and said it should dry in about 3 weeks.

I will not use quartzite again

Yikes. As awful as it is, you found a leak you didn’t know you had. This may have saved you from other bigger problems down the road.

Your sink is leaking.

No the faucet was not sealed nor the cut edge holes in quartzite

That ain't faucet leaks. Faucet leaks are circular. Your sink is leaking. Try slipping a thin knife between the bottom of the stone and the sink flange. Bet there's no caulk.

The membrane under the stone was full of water

There was caulk between the sink and top. But maybe not enough. The installer added more. Still hoping it dries. Thanks for info

We just had these quartzite counters installed in July 2020. Looks horrible. Contractor claims he's never seen this b4. I'm so disheartened. I told him to bring the fabricator out to look at it. Waiting...

This happened to me. The fabricator did not caulk between the sink and the stone. Once it was sealed, it was fine.

So what are better for kitchen countertops?

Once it gets sealed will it dry up??

Having a lot of issues with our and the fabricator has not responded to come back. It’s been about 4 years now after install and it’s just worsening.