Quantitative chemical analyses (46 spots) were
carried out on 15 faceted emeralds at the electron microprobe
facility of the Institute of Earth Sciences, Free
University of Amsterdam, using a JEOL model JXA-
8800M instrument. Analyses were performed at 15 kV,
with a beam current of 25 nA and a spot size of 3 μm.
The count time was 25 seconds for major elements and
36 seconds for most trace elements (50 seconds for V,
Cr, and Rb).