Conservation Highlights: Gold - Noble, Precious, and Rare

As you have been following along with us, you have probably become aware of the scarcity of goods made from precious metals found on Queen Anne’s Revenge. This was highlighted previously when we showcased two very small jewelry fragments, the largest gold artifacts found to date. The majority of gold from Blackbeard’s flagship occurs in the form of gold dust, 240 vials of which have been recovered from dredge spoil using a microscope, precision, and time. While 240 vials of gold dust might sound impressive, the key word here is dust. Notably, some of the gold dust from Queen Anne’s Revenge is contaminated with mercury. Due to the poisonous nature of mercury, once identified it is stored in a separate vial.

Very little must be done to conserve gold. This is because gold is the most noble of metals and therefore is the most resistant to corrosion or oxidation. When un-alloyed or pure gold is found, often the only procedures that are necessary are documentation (with photography and illustration, as well as research into the object itself – how/when/where it was manufactured) and proper storage.

Gold forms stable alloys with many other metals and can also be found as gilding. In this case, when the gold is found as part of another artifact, like a gilded brass pocket watch balance cock recently discovered, the treatment takes on a more traditional path. The artifact is removed from concretion using an airscribe. If the object is gilded, special care must be taken to ensure the gilding remains in place as best as possible. Once the metal becomes exposed, often it goes through XRF testing to confirm which metals are present. Here too, once identified, the gold will require no further treatment though the rest of the object may require additional conservation depending on its composition and condition.

In a nutshell, gold comes out of the ocean in most cases just as shiny and gleaming as the day it went in. This inherent stability is why gold retains its value so well and probably the reason that we don’t find much of it – the pirates would have offloaded anything of high value when the ship was abandoned 300 years ago. They would not have left all of that wealth behind!

Sources:
-Cronyn, JM. The Elements of Archaeological Conservation. London: Routledge. 1990.

Images:
-Snipped gold jewelry from the QAR site. Image by NC Department of Natural and Cultural Resources.
-Searching for gold dust in the sediment from the QAR site. Image by NC Department of Natural and Cultural Resources.
-Gilded brass pocket watch balance cock from the QAR site. Image by NC Department of Natural and Cultural Resources.