We have bluestone paving outside, and while admittedly we have hard winters so it is exposed to temperature extremes here, I wouldn't recommend it for a counter - it seems to flake a lot, with whole millimetre-thick-but-half-the width-of-the-slab sized pieces coming off now and then.

It looks wonderful, but I just don't see it for counters. Indoor flooring, if the slabs were carefully selected, perhaps.

Hi,
From what I understand, it's a GREAT choice for a countertop but requires a little care, like all other stone. Google "bluestone for kitchen counters". An island was topped with it on a recent episode of This Old House. I LOVE bluestone, I have it all over my yard. I like how my daughter uses smaller rocks and scratches "pictures" into the bluestone stair treads on my porch and they just magically disappear. It's gotta be bullet proof. Here's a link for you, there's a lot of info on them out there, good luck!
http://en.allexperts.com/q/Construction-Contractors-1093/bluestone-countertops-kitchen-care.htm

Another, this one has pics and I'm EATING MY HEART OUT, why didn't I think of this?
http://www.countertopsofthefuture.com/Solid_Surface/Devonian/devonian.html

Here is a link that might be useful: Bluestone for Kitchen Counter

I have a bluestone backsplash and really love it. Never thought about it as a material for a countertop. Hmmmmmm.