People are likely to tell you to do a search--which is a good idea. There have been several threads on this in here and I definitely found them helpful. In the meantime, I can tell you that I have carrara on my perimeter countertops. My GC and KD both said "NO WAY" in the beginning, but I forged ahead! Mine have been in for about six weeks and I love them. The biggest cons you'll hear are staining and etching. I haven't had any staining issues at all. My husband left a lid from a margarita mix container on one counter and it did etch (acidic). But I'm pretty sure I'm the only person who can find it. What you'll generally hear on here is that if you're willing to live with some "patina" meaning some etching and possibly staining (though there are poultice recipes that people seem to have great success with), then marble is a great choice. If you want a completely blemish-free surface, it may not be for you. Definitely do a search on here, though--and good luck!

Never EVER E V E R put vinegar on marble! It will eat it and dull the finish..... If that has not happened, your counter is not marble....more likely some sort of composite....or a quartz with a finish that discolored. I would call someone who deals in stone counter tops. I know that the quartz counter tops have a coating that is heat sensitive.

FWIW I got a Swanstone counter with integrated sink in white. Its solid white (and I love it - so easy to clean). Bought it at big orange for cheap, after reading so poor reviews for cultured marble (which wasn't that much cheaper).

See if you can run a steak knife between the bottom of the stone and the sink flange. If so, your sink is leaking and trapping water there. The stone is sucking up the trapped water. The solution would be to drop the sink, let it dry completely, #40 peroxide (beauty supply store) the crack, superglue the crack with the runny stuff, seal the stone bottom, silicone the sink flange and strap it in place, then seal the top.