trofluorometer compared to spectra obtained from the CCD spectrometer. The spectrofluorometer data show ZPLs for the N3 and H3 centers at 415 and 503 nm, respectively, along with their related sidebands. Due to the lower resolution of the CCD spectrometer, only the sidebands are observed in figure 7 (right). A yellow diamond had a weak fluorescence spectrum, and a violet diamond showed a moderate fluo
rescence spectrum. Four irradiated diamonds also showed category 2 fluorescence: weak spectra were measured for the brownish orangy yellow and bluish green samples, and strong to very strong spectra were obtained from the greenish yellow samples.
Absorption Spectra. UV-Vis-NIR absorption spectra were collected for four natural and three treated