My recipe for transfiguring to get plutonium is first row, all silver, second row three gold and one stack of platinum, or iridium or any other higher level metal. If you stack the silver and the gold and everything else you get more ingots back. The result should be a minimum of one compendium, one plutonium and possibly one iron. You get higher grade metal if you stack more silver and gold and can bypass the iron. I haven't tried it with any other metals because all I had on hand was silver, gold,platinum and iridium.