Monthly Archives: November 2011

Iron gall ink or not?

After being unable to see some of the ink on our parchment scrolls we began a study into which of our collection of parchment samples had iron present and which did not.  To assess the level of iron present in our parchment samples we used X-ray fluorescence (XRF). XRF is an excellent non-destructive analytical technique for chemical analysis.  An example spectra collected from two of our parchment samples is shown below where a clear iron peak is visible in the one sample and is missing in the other sample.

We found that most of our parchment collection had a presence of iron to a certain degree but using XRF we have now identified which parchment samples had a low fraction making them difficult to see.

The above graph shows the X-ray fluorescence spectra for two of the parchment samples in our collection dated 1775 and 1817.  In the parchment dated 1775 there is a peak present at 6.3 keV resulting from the presence of iron (Fe).  The parchment sample dated 1817 displays no visible peak at 6.3 keV demonstrating that there is very little iron present in the ink.
The above graph shows the X-ray fluorescence spectra for two of the parchment samples in our collection dated 1775 and 1817. In the parchment dated 1775 there is a peak present at 6.3 keV resulting from the presence of iron (Fe). The parchment sample dated 1817 displays no visible peak at 6.3 keV demonstrating that there is very little iron present in the ink.