I hit the motherlode of precious metals on one of my fortresses, 50 dwarves each had a platinum cabinet table throne door armor rack weapon rack statue and chest all decorated with gold and silver as well as a bed decorated with gold and platinum silver and electrum. Each of the dining rooms had solid gold walls, floors, tables, and chairs with platinum statues all menacing with platinum and silver. All of the bridges were gold and all of the roads were platinum. We exported platinum silver and gold crafts and wares so much that I just cleaned out all of the caravans to have fewer of them. I built platinum cages decorated with silver and gold and filled them with exotic beasts for my dwarves to enjoy. My trash heap was made with platinum walls and gold floors and my graveyard was made of silver and platinum.
Well with the death of half my dwarves to combat a disasterous building project and a series of horrible accidents most of my fortress was dead or insane. I considered rebuilding but by now your tired of seeing platinum silver and gold and so was I which is why I flooded the entire first level and most of the surrounding area with magma and abandoned it. I imagine there are still stories of the forever burning city of mad Dwarves filed with unquantifiable and completely unreachable treasures.