Fig. 4: FTIR spectra of representative artifacts from different material categories.
Left 1: marble; right 1: nephrite & serpentine; left 2: shell; right 2: quartzite; left 3: mica; right 3: malachite; left 4: turquoise; right 4: black talc.
Fig. 4: FTIR spectra of representative artifacts from different material categories. | npj Heritage Science
