Box sieves (like the one in the animation below) and hand held sieves (like the ones in the photograph above) are commonly used to find small objects the eye might have missed. Nested sieves (each with a finer mesh than the one above) allow the separation of objects of different sizes. They all use wire screens -- much like the ones we use in windows. It is always easy to miss things during an excavation. Sieves give archaeologists one more chance to make sure there isn't anything left in the soil or sand removed during an excavation. In Nubia, sieves are often used to find beads, bits of faience (glazed clay), small bones, pieces of metal.
Sometimes archaeologists use a process known as "wet sieving." In wet sieving, the sieve is filled with sand or soil, then dunked in water to dissolve its contents. The dissolved material falls easily through the screen, leaving behind any objects. Small organic (once-living) remains such as seeds and bone might also float and be separated in using wet sieving.
