When we’re in the midst of an archaeological dilemma, we occasionally take a trip to the dentist. A good teeth cleaning may not spark a miraculous breakthrough, but for us, it sure does help when you have a local dentist willing to share his X-Ray machine for our research.
Believe it or not, having access to an X-Ray machine can make a real difference in identifying crucial aspects of an artifact. We recently used Dr. Gregg Stein’s equipment to uncover some of the hidden details of an 18th century British coin we found during an excavation.
No Teeth Necessary
Although it’s unusual to think of using X-Ray machines for anything other than examining the features of the human body, they can be particularly helpful when it comes to detailing various metal items. Over time, metal coins and artifacts become terribly corroded, leaving archaeologists unable to identify crucial dating features with the naked eye. X-Rays can penetrate this corrosion and illuminate these important details. This technique works on certain metals better than others. It appears that the x-rays work best on pure metals, as opposed to alloys. In the case of recently uncovered coins, this has proven to be an important tool.
We initially used X-Rays during our City Hall project because dating the deposits was key to constructing a timeline of our discoveries, and in turn, the evolution of the project site. The area around NYC City Hall has been densely populated since 1735 and any tool we can use to help us create a more accurate timeline can give us a better interpretation of the excavation site. Our first x-ray provided us with the detail for this 1746 British coin.
Another allowed us to identify what we thought was a button as a deliberately perforated Spanish coin. This coin reads “Hispania” and it may have been perforated to allow the owner to sew it their clothing for either safekeeping or as a talisman.
The Importance of Coins
Coins hold significant historical value. Their symbols and design reflect a society’s culture, economy and even religion. And because of their metallic composition, they often survive for many years in better condition than wooden or ceramic objects. Even the smallest artifact is significant…thankfully, Dr. Stein agrees!