Fig. 2
From: Ammonium alum in alum-treated wooden artefacts: discovery, origins and consequences
μFTIR spectrum of (NH4)2SO4 from spot analysis of grain from fragment 185-6
Fig. 2 | Heritage Science
From: Ammonium alum in alum-treated wooden artefacts: discovery, origins and consequences
μFTIR spectrum of (NH4)2SO4 from spot analysis of grain from fragment 185-6