Sodalite with special fluorescence from Norway
Sodaliet and albite, Sagåsen Quarry, Auenlandet, Porsgrunn, Vestfold og Telemark, Norway. The piece has sodalite in a blue and a grey colour. The blue part has a nice blueish green fluorescence due to Mn2+ (spectrum peak around 490 nm @ 275 nm excitation). The grey part is more orangish because there is also a red contribution from Fe3+ (spectrum peak around 690 nm @ 275 nm excitation). As a comparison also the red Fe3+ emissions from feldspar are shown. The grey sodalite has a stronger orange S2- fluorescence due to the presence of trivalent iron (Agamah (2020)). The red fluorescence in the UV-C is from trivalent iron in albite. Spectra are preferrably taken at 275 nm because those LEDs have less ghost emissions in the UV-A and visible, but 255 nm gives the same image result.