Hello. I love Houzz and these forums, they are so helpful. We moved into our house a year ago. Bluestone was our choice for our mudroom flooring. We liked the idea of carrying the exterior entrance stone to the interior of the house. That all being said, when the builders were here they weren't careful (no matter how many times I reminded them) about covering the stone when they were working and it got blotchy and cruddy quickly. So upon their exit of the house they cleaned the stone at our request. I feel like they really did a number on it when they cleaned, I don't know what they used. I had a stone specialty person come in, steam it and and high power wash it a few months ago a big machine, but it didn't seem to help. He said it looked like they used acid to clean it. He wasn't sure what more he could do. The bleached out patches around the grout lines kill me. Any help would be greatly appreciated. Thank you.