Little plate of pink rhodochrosite crystals, all packed together. Contrary to every guess, the rhodochrosite is fluorescent red under both shortwave and longwave UV light, much dimmer under midwave UV. Rhodochrosite is not supposed to be fluorescent: too much manganese is usually considered to be “self-quencher” for the fluorescence.
Fluorescence under longwave UV light.
Normal light.
I checked this specimen via Raman spectrometry. The spectra matches the reference for rhodochrosite MnCO3, and is significantly different from calcite CaCO3 and kutnohorite MnCa(CO3)2. But note, Raman spectroscopy is not the best technique in this case, and a quantitative elemental analysis, like EDS, would be much more conclusive to determine how much manganese and how much calcium is present.
Label from Earth’s Treasures.
