Fig. 5
![Fig. 5](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs40494-020-00449-1/MediaObjects/40494_2020_449_Fig5_HTML.png)
a XRF spectrum acquired from the gourd’s white decoration outlines, displaying prominent mercury (Hg) peaks from calomel and silver (Ag) peaks from the underlying silver leaf. b Raman spectrum collected from the same area, revealing the characteristic bands of calomel at 167 and 275 cm−1. The area analyzed is marked in the object image with a red rectangle and arrow