Axel Emmermann MKA
Jan 4, 2017
Cuprian powellite: Jardinera No. 1 Mine, Inca de Oro, Chañaral Province, Atacama Region, Chile.
The yellow fluorescence of powellite, which is intrinsic, is colored slightly greenish by traveling through the crystal mass. Just like sunlight is colored by stained glass. You can look at the spectrum (or download it) here.