Inclusions in 15 samples were analyzed by Raman
spectroscopy using a Thermo DXR Raman microscope
with 532 nm laser excitation. UV-Vis-NIR
absorption spectra of six representative samples (one
cabochon, two faceted, and three parallel plates) were
taken with a Unicam UV 540 spectrophotometer in
the 280–850 nm range. Mid-IR spectra of 16 representative
samples (one cabochon, 14 faceted, and one
parallel plate) were collected using a Thermo Nicolet
Nexus FT-IR-NIR spectrometer.