The chemically bonded water, in the form of hydroxyl groups (single atoms of hydrogen and oxygen bound together), forms water vapor and evaporates.
“When you do that, you mimic what the sample was like when it was originally fired,” says Bowen. Over the next several weeks, the ceramic will react with water in the air and gain weight.
They can be downloaded for personal use but if you are not a Leicestershire Fieldwork member and wish to use these as course material or in any other way please contact Leicestershire County Council for copyright permission and agreement.
– Please contact us to discuss the nature of your research objective to ensure the most appropriate material selection and pretreatment of your pottery sherds.
All sheets except the one on flint have been put together by fieldwork member Andy Kirkland.
The flint guide has been done by Brian Burningham and is ten pages long, all other sheets are one page.
The 18 sheets cover pottery from the Neolithic to the early 20 Century.
The largest piece of pottery we found in this unit was a large rim piece with red paste and brown lead opaque enameling, which, by its texture, appears to be hand thrown.It takes advantage of ceramics’ predictable tendency to bond chemically with water over time.“It’s simple,” says Bowen. This removes any dampness that the ceramic might have absorbed.Then, weigh the sample and put it in a furnace at 600 degrees Celsius.By comparing pottery sherds found in the three Unit 6 SUs, we were able to determine that the three SUs date back to nearly the same time, as we found matching and similar pottery sherds across the SUs.Some of the sherds from different SUS (the three excavated this year and those excavated in the past) have the same paste and glaze and many are similar in their texture and coloring.In general the burned food residue has to be a patina that can be removed in small bits or chunks rather than a sooty powder.