We had Mont Blanc quartzite installed 9 weeks ago. We were told at time of installation it was installed wet so we could not seal it. There were visible wet spots on the stone. The spots have faded but still noticeable. New bright white spots appeared immediately after the 3rd time our fabricator used a BernzOmatic torch on it. It still has not been sealed so we are still without a functional kitchen. A moisture meter is reading around 16%

on the wet looking areas so this tells me it is dry. Our fabricator is saying to seal the stone and the wet marks will eventually fade away. I am concerned the stone is stained and the wet/white spots will not disappear. Does anyone know if these spots will fade or if in fact the stone could be stained? Reading online looks like the white spots could be efflorescences. I have included photos of day or install (second photo) vs now.