Pottery shards are items used in crafting different pottery. They can be found via sifting dirt, sand, or gravel with a sifter. There is also a small chance of getting one by putting relic scraps into an analyzer.
Three pieces of pottery can be crafted with them: broken amphoras, broken kylixes, and broken volutes. These broken pottery items can then be fixed in the archeology workbench. The player can achieve the "The Amazing Vase!" achievement after crafting their first piece of pottery.