I need advice about my brand new grey marble pool deck and pool coping, which was just installed. We were thrilled with the work, looked so beautiful and our pool patio renovation project was almost done. Our pool reno project manager said he would have the patio washed (a mix of 10% muriatic acid and 90% water) to finish up the project. I looked at the patio a short while after he finished and noticed my beautiful patio turn from variegated hews of grey (light and dark streaks and mottled, etc.) to a mottled dull finish with many chalky looking areas throughout the deck and also the pool coping. The whole area is now stripped of much of it's formerly beautiful colors. I am looking for a way to either restore the patio and coping to their former look and feel or a way to better explain my concerns to these experts. The pool project manager shared he has used this method of final cleaning on marble, and other surfaces, for many years and never had a problem, until now. He said he can pressure wash and perhaps buff and then seal the patio and that will fix the issues of chalking / cloudy looking tiles and coping. I know that just before the wash my patio looked beautiful, and directly after the acid solution "wash" it doesn't. I want others' opinions because I am at a loss about what my next steps should be. Any suggestions are very welcome and appreciated.