Upperpart:secondderivativecalculation(dottedline)oftheRamanCH
region (solidline).Thebandpositionsareindicatedwithastarunderthesecond
derivative.(a)Mastic;(b)archeologicalcopal(blackline:internalsampling,gray
line: surfacesampling).Lowerpart: fitting resultsoftheRamanCHmassif.
Experimental spectrum:blackdottedline,calculatedspectrum:solidredline,
decomposition bands:solidgrayline.(c)Mastic;(d)archeologicalcopal(internal
sampling). Itturnsoutthatthedecompositionbandsarepreciselyatthepositions
that weregivenbythesecondderivative.(Forinterpretationofthereferencesto
color inthis figure legend,thereaderisreferredtothewebversionofthisarticle.)