Zircon, golden, fluorescence spectrum
These plots show the yellow fluorescence of a natural yellow/brown zircon. The image shows the stone illuminated by UV light around 370nm. The two spectra show the broad band emission when excited by 254nm Hg light (orange line) and by 365nm LED light (blue line, shifted up 10 units for clarity).
The thin grey lines show gaussian profiles, computed in photon energy space, fitted to the two spectra and plotted here in wavelength space (which makes an asymmetric profile broadened to the red). The fit parameters are shown on the plot ('Gauss_1' referring to the 254nm spectrum).
The fact that single gaussians fit so well supports the notion that this radiation-induced colour centre fluorescence is a single process acting within the crystal.
Such stones have been subject to accumulating radiation damage produced by neutrons and alpha particles emitted during the radiative decay of uranium and thorium impurities over hundreds of millions or even billions of years.
Note that this measurement can only be made with a flux-calibrated spectrometer having a well determined conversion from spectrometer counts to (relative) energy per unit wavelength.
Zircon, golden, fluorescence spectrum
These plots show the yellow fluorescence of a natural yellow/brown zircon. The image shows the stone illuminated by UV light around 370nm. The two spectra show the broad band emission when excited by 254nm Hg light (orange line) and by 365nm LED light (blue line, shifted up 10 units for clarity).
The thin grey lines show gaussian profiles, computed in photon energy space, fitted to the two spectra and plotted here in wavelength space (which makes an asymmetric profile broadened to the red). The fit parameters are shown on the plot ('Gauss_1' referring to the 254nm spectrum).
The fact that single gaussians fit so well supports the notion that this radiation-induced colour centre fluorescence is a single process acting within the crystal.
Such stones have been subject to accumulating radiation damage produced by neutrons and alpha particles emitted during the radiative decay of uranium and thorium impurities over hundreds of millions or even billions of years.
Note that this measurement can only be made with a flux-calibrated spectrometer having a well determined conversion from spectrometer counts to (relative) energy per unit wavelength.