Sorry I dont' have a direct answer to this as I'm not that informed on calamine.

HOWEVER Mario Badescu Drying Mask (which everyone including myself rave about!) contains it. My mom smelled it after I put it on and asked if I was putting straight Calamine on my face. I said I didn't know what the was and she said it was made to make skin less irritated and that you'd put it on if you had some sort of rash.

Although it is not the main ingredient, I think it does help soothe my skin and prevent irritation and inflamation. I just read online that a lot of people use it for rosacea because of this.

As for controlling acne, I doubt this would make any major impact with out the combination of another product that would actually dry up the acne. If you have dry skin I would recommend it though, as it seems it may nourish the skin to prevent it from shedding and then those skin cells clogging the pores (exfoliate!)