Marks appearing INSIDE granite

   Hi, we had Marron Cohiba countertops installed in our kitchen a couple of weeks ago. I might be being paranoid (as I keep 'inspecting' it!) but I think I am noticing marks appearing INSIDE the granite. The granite is a mixture of blacks and browns and bronzes (best way I can describe it) with a few small fissures running through it, it is also known as Antique Brown I think. Well anyway, there are a few areas where there are white-ish marks appearing inside the granite (not stains on the surface). A couple of them even look like they might have a greenish tinge to them (like when mold forms). I can not explain it any other way but I don't think it was like this when it was first installed. The marks are about small fingernail sized or smaller (not uniform shape) and look like the stone is changing / has changed inside. Hope this is making sense? Anyway, anyone got any advice or experienced this before? Don't know what it could be. The installer sealed the granite so don't think it could be something from the top surface penetrating down. Could the stone change once installed? Any advice welcome, even it is from another owner of Marron Cohiba who explains this is normal with this stone and I just didn't notice it before! thanks!!