Raman Binary Mapping of Iron Age Ostracon in an Unknown Material Composition and High-Fluorescence Setting—A Proof of Concept

The textual evidence from ancient Judah is mainly limited to ostraca, ink-on-clay inscriptions. Their facsimiles (binary depictions) are indispensable for further analysis. Previous attempts at mechanizing the creation of facsimiles have been problematic. Here, we present a proof of concept of objective binary image acquisition, via Raman mapping. Our method is based on a new peak detection transform, handling the challenging fluorescence of the clay, and circumventing preparatory ink composition analysis. A sequence of binary mappings (signifying the peaks) is created for each wavelength; their legibility reflects the prominence of Raman lines. Applied to a biblical-period ostracon, the method exhibits high statistical significance.