Well this is odd. two days ago the crack stopped short of the under mount sink and today the crack has spread down to the lip of the under mount marble rim area. We have not even used the bathroom. I didn't know a crack could travel{{gwi:807}} like this.

This is the best close-up I can get. It starts at this end and did stop short of the sink. However, today (still have not used bathroom) the crack had spread to marble lip on under-mount area.

I can not get a good picture due to the glare. First picture shows the crack and in 2nd picture the crack is in between the pencil line for more clarification.

This post was edited by jterrilynn on Mon, Jan 21, 13 at 15:43

If you can't snag a fingernail on it I wouldn't worry about it. If it is irregular in a few areas a good fabricator can patch it so you'll never notice it. what you are seeing isn't common but it does happen with natural stone on occasion. if the crack was proximate to the sink cutout I'd be a little suspicious of the install but given the location it looks like the stone is just being stone. a very thin viscosity adhesive (think crazy glue)can be applied to the crack. It will wick into the stone and prevent the crack from separating. (It shouldn't separate anyway if its properly installed because with proper install there is no mechanical stress on the stone to pull it apart.)

I agree with oldryder looks like a weakness in the stone.
Should be sanded to smooth out the rough spots possibly.The using a cyanoacrylate(ca or crazy glue)it can be repaired and repolished. The fabricator should be able to handle that repair.If he cant for whatever reason find a bone fide stone refinisher to handle it.
Use clear glue so the repair looks like a natural vein or fissure.
Dont let them open it up and fill it with colored polyester(like epoxy but easier to work with)