@kreatora That might be it the connection, sims that have higher archeology skill have a higher chance of finding the higher and better quality items, both in dig piles and treasure chests. The Asperation also helps too. Anyways I think that is why it comes out of the dig piles as lumps of clay, so that the quality and the generality can be determined if its a fake or a real genuine item. I believe you can turn dig piles into excavation sites that may increase the chance at finding more quality artifacts.