Hi Larry, I have a marble hearth and I've been following this thread with interest. I'd like to seal it to prevent the finish from dulling. I went to Home Depot and looked up and down the tile, flooring, and paint aisles, but couldn't find the mineral spirit-based silicone sealer you referred to in your last message. The closest I came was silicone caulk. Can you tell me a brand name possibly? Does it go under any other name?