cutting stone and finding aluminum

In this dream, actually in the middle of last night, I was in my father's office, which had been carved out of stone in the side of a mountain. The furniture was partly wood, partly stone, with a stone desk. There were other people hanging about, like goats, here and there on the side of the mountain. My dad was trying to remember where he put his papers. Somebody (I think it was my brother-in-law) showed me this slab of stone, like a countertop, that he had cut out of the side of the mountain, and it had a large shiny piece of aluminum embedded in it (I know, but this is a dream!). And so I was keenly interested in getting more of the same, and we went to look where this piece had been cut to see if there was more like it.