Archaeologists study ancient peoples by the items they left behind. These artefacts may be old buildings, tools or pottery. According to the The International History Project, sometimes the only remains found from civilisations are potsherds, which are pottery fragments. Archaeologists examine the markings and try to piece all the information together to learn more about ancient people. To study potsherds in archaeology, scientists follow eight steps to properly clean and record these excavated findings.
Photograph the found pottery sherd in situ, or where it was exactly found. It is not moved until other pottery sherds are carefully looked for in the same area or locus. The pottery sherd is recorded in a notebook initially. In this retrieval step, soil around the pottery sherd is sifted to try to find more fragments. Then the fragments are placed into a plastic bucket and tagged with water-resistant tags and permanent marker.
Soak the pottery sherds in a pail of water for a couple of hours to prewash the fragments. The soaking loosens the dirt for washing. The sherds are scrubbed with brushes to gently clean them. Sherds with writing on them are given special attention and noted. After the washing, the sherds are placed in a mesh bag to dry overnight.
Divide the dried sherds into pieces with markings, drawings or large sections such as rims, bases and handles. These are called "diagnostic sherds," which can be read by a special ceramic archaeologist and identified. Other pieces are called "body sherds," which may be reassembled into complete pottery.
Record all the pottery sherds into a special journal. Unique identification numbers are assigned to publishable pottery sherds that distinguish them from any other pottery sherds in the world. Clear nail polish is painted on an inconspicuous part of the sherd, and then the number is written with India ink and then sealed again with another layer of clear polish.
Saw the pottery sherd with a diamond-blade saw to cut a cross section of it for examination and drawing. The longest part of the sherd is sawn while leaving its identification intact. This is called the cutting stage.
View the interior of the sherd with a comparator, or magnifying optical instrument. Archaeologists use the grid inside the instrument to measure any voids or shapes within the sherd. Fragments in the clay are noted and any surface treatment, such as slip, which is wet clay used to paint it, is noted. The archaeologist is trying to date the piece by figuring out how it was fired, what type of clay was used or whether a pottery wheel was used.
Draw the pottery sherd with drawing paper and pen in the drawing stage. A drawing can give more information than a photograph and archaeologists trace the sherd and ink it in. The exterior lines are all traced, inked and then scanned into a computer.
Publish all the findings from the pottery sherds in archaeology publications. All pottery excavation reports are published in specialised journals so scientists from around the world can learn about each dig. Archaeologists can see similarities from other parts of the world and analysis can be made from a wider audience of scientists.
New scientific methods of slicing microscopic pieces of pottery sherds are now being used to examine them under a microscope. This helps archaeologist determine the geology of the sherds. Neutron activation analysis is another recent technology that studies the chemical elements that make-up the clay. Once a dig is finished, many pottery fragments are shipped to the U.S. for further examination.