I think it'll be OK. I know I have some drops on my counter and a couple of others around the house from doing samples, and they will not come off. I would keep it waxed and give no guarantees. Keep it waxed with a thick wax.
Its kind of a hypothetical answer, but Id give it a shot.

These products are durable , but think about the products used in bathrooms. Alcohol,soaps,hairspray,perfume Etc.

M. Peacock,

I have actually given counter tops much thought. I am remodling my entire house and I want to install plastered counters in my kitchen. A brave move, but if it is done right, it should work. This is how I intend on doing mine...

(If I am wrong, Doyle, Luca, please correct me)

I would pull off the formica and have the wooded surfaces covered with a water resistant barrier like cement board or the stuff that they put in shower stalls, I can't remeber what it is called, I think that it is blue board, maybe fiber rock. I would check into it. Some builders even put roofing felt between the wood and the cement board. A counter top is a much used surface. The substrate needs to be solid and protected. Then I would apply Velnova, which is similar to prontomuro, but it has a cementous base. I am not sure if the client wants any type of a design, i.e. tiled look, stone look, etc. Velnova will accept the resin based products. Stay away from the true lime products, they will deteriorate from the water over time. Veneziano or another resin plaster will work excellently. Granted, the Veneziano will have a more textured look, "resin montavano", but that is the combination that I feel would work best. I would even consider a polyurethane or aquathane. Doyle, Luca? Help me out here.

Counter tops I would do in my own home but don't think I would do for a clients home. If you do I would put a good poly on top. Waxing a counter top sounds like a health issue to me. When we did ours, we cleaned the top and primed with XIM and then started the application cycle. I would stay away from the natural products like Marmorino and use the resin base plasters. After, apply a water borne poly like BM maybe two coats sanded inbetween. Will choping with knife on counter top hurt the surface? I would say yes. We always use a chopping board on ours.
The best advice I can give is try it out on a sample surface and try to put it thru the punisment a real counter top would get. And then let us know the out come.
Doyle

If it were mine, or a clients, I dont think I would do it at all. Plasters are made for walls in my opinion.

You have to think about the abuse it will take. Not to go back on my word, but I would stick to a laminent, in which I think is almost indestructible, tile which is baked on, or granite. Other than that I dont think it will hold up. Maybe in a powder room with not much use I would do a plaster. The Resin based products still tend to "dent", the lime chip.

Just my opinion.

I would never do a counter top in these plasters. I feel there is to much traffic around counter tops.To many possibilities for damages. Overtime i cant see how they would stand up. Stick with formica or granite.

Can you use a BAR poly.to give the added protection it needs?

I currently have a buttler's kitchen with a ceramic tile counter top. I intend on plastering it in Stucco Valentino. I don't think I would try it on a client's counter top but I will not sue me. The buttler's kitchen is rarely used and if the counter top cracks it will blend in.

How about granite?

HI, you could place a sheet of toughened 4mm glass on top

Just to let anyone know this, I applied a bar poly to a stucco valentino counter top for a bar. So far it has been 3 months and there is no signs of cracking. I was a little hesitant at first so I waxed the bar. My client wanted to protect the bar from heavy usage so he sanded the surface lightly
then wiped the bar down with a moist cloth,then let it dry before he used the poly. He also framed the bar with a molding and had the edges of the molding sticking up to avoid it running over the sides.

Hi,
I just tuned in to learn about what you pros have to say about plastering countertops. As a professional having been around the wood finishing industry most of my life, my comment is directed toward the idea of using poly for the protective coat. You guys probably already know this but, if you're going to use poly, over time, whether you use a cutting board or not, the poly is going to recieve scratches. Secondly, polyurethane, whether water based or oil, doesn't matter, isn't particularly water resistant. If there is ANY spot or area that's not completely sealed, water will find its way under the poly and it will lift. The idea of glass suggested by Tower Home Improvements will definately prevent scratches but the beautiful plaster will look sad under that glass. Poly if you want to but within 2 - 5 years expect to refinish it... at least portions of it. BTW, did you ever see an exterior door that was polyed? It becomes flake city. Poly is good for interior floors and trim.

signing off...long winded!
Tom