Sunday, November 13, 2016

More on the dating of ancient ink

In-depth Study of Raman Spectroscopy on Carbon Black Ink as a Potential Method for Non-Destructive Dating of Ancient Manuscripts

Sarah Goler

Publication Date
Wed, Apr 15, 2015

Academic Term
Fall and Spring

Academic Year
The abstract is as follows:
Sarah Goler
April 2015

In-depth Study of Raman Spectroscopy on Carbon Black Ink as a Potential Method for Non-Destructive Dating of Ancient Manuscripts (Abstract)

Micro-Raman spectroscopy is a non-destructive light scattering technique that can be used to distinguish physical and chemical properties of materials. We have performed micro-Raman spectroscopy experiments on the black ink from Egyptian manuscripts of known provenance ranging in date from 300BCE to 1000CE. All the black ink showed the typical spectrum of carbon black ink with broad D and G bands. The D band is a forbidden Raman transition that occurs when the lattice symmetry is broken. The D band at approximately 1350cm-1 is associated with disorder, vacancies crystalline edges, etc. The G band at 1585cm-1 is a Raman allowed transition that arises from the E2g in-plane vibration of sp2 bonded carbon. These features in the Raman spectrum of carbon are assigned to the crystalline and amorphous carbon content. The carbon black spectra observed showed clear changes with the age of the ink. The significance and number of peaks to fit the Raman spectrum of carbon black is not well understood. We selected to fit our data with two, three, and four peak fits to try to extract quantitative and qualitative insight from the spectra. We found that all the parameters from our two peak fits show correlations with the age of the ink that could potentially be used to non-destructively date ink of unknown date.
Stephen Goranson drew my attention to this paper, which is of interest in relation to the recent announcement about advances in dating ancient ink, with reference to the Gospel of Jesus' Wife. As far as I know, there have been no formal publications about the dating of the ink of that particular manuscript. This paper is described as a "working paper" of Columbia University's Italian Academy For Advanced Studies in America. I take that to mean it is still a work in progress, but it seems to give some idea of what is going on. Stephen also writes:
*If* the above abstract is the sort of research proposed--which I do not know--then it would be appropriate to note that the contribution by Ira Rabin in NTS 2015 has already offered reason to question the potential of such approaches to deliver reliable dating. Further--reportedly--two lectures at the September 1-5, 2015 8th International Congress on the Application of Raman Spectroscopy in Art and Archaeology in Wrocław, Poland may include explanation why such approach to dating would be unreliable.
We'll see. I am not qualified to have any opinion on the validity of the methods used etc., but I hope the discussion moves into the peer-review literature as soon as possible, so that those who have the expertise can evaluate them.

Background here and here, with many, many links.