Material Evidence: Clark

7). RAMAN SPECTRA

Clark indentifies the components of the ink, using a different technique.
Brown, K. L. and Clark, R. J. H., 2002 Analysis of pigmentary particles on the Vinland Map and the Tartar Relation by Raman microprobe spectroscopy Anal. Chem. 74, 3658-3661.

Lamp
Soot from a lamp is used to make carbon ink. (It is fixed with gum Arabic.)
Wasps
Iron gall ink is made from oak galls. Oak trees make galls to forestall attack by wasp larvae.
H
Carbon-ink lines do not deteriorate over time.

BACKGROUND:

Raman spectroscopy indentifies molecules unambiguously. Each has its own characteristic Raman spectrum, indentified by matching against standard spectra. Here Clark uses this different technique to indentify the molecules on the surface of the VM.

Manuscripts Small
Iron-gall-ink lines, over time, cause yellowing and can destroy the manuscript.
Spectro Small
A Raman spectrometer examining the Vinland Map.

FINDINGS:

  • Anatase is found in the yellow ink line of the VM but not elsewhere on the parchment.
  • Carbon is found in the black ink line of the VM. The black ink is a carbon-based ink.

Anatase Graph1 Small
A Raman spectrum of the yellow ink, showing anatase.
Anatase Graph2 Small
A Raman spectrum of the black ink line shows carbon, identifying the ink as a carbon ink.

COMMENTARY:

Two different findings by Clark confirm that the VM is a modern forgery:

  1. Clark's finding of anatase in the VM ink, confirms McCrone's findings of anatase in the VM ink. (McCrone showed the VM to be modern by showing the anatase to be modern.) The anatase cannot be a contaminant. It is not distributed uniformly on the Map.
  2. Clark identifies the black VM ink as carbon-based, a very stable ink. On the VM this black ink is surrounded by yellow coloration. Only unstable iron gall ink produces yellow coloration, as it decays over time. Hence the yellow coloration has to have been added - most plausibly by a forger trying to make the Map look old.

QUESTIONS:

  • What role does Clark's study play in establishing the status of the VM?
  • Does Clark's study resolve the controversy between McCrone and Cahill?