Calcite Crystal with Organic Inclusions, Linwood Mine, Buffalo, Scott County, Iowa
These macro photographs show a very interesting multi-wavelength fluorescent response in a single, modified scalenohedral calcite crystal, part of a much larger specimen from the Linwood Mine, Buffalo, Scott County, Iowa. Under both long and short wave UV, the crystal glows white from within, and this zone of fluorescence corresponds to an internal tan/brown region within the basal half of the crystal, evidence of a likely organic acitvator. The tan region can be clearly seen in the visible light photograph. Under short wave UV the surrounding smaller crystals also fluoresce a beautiful soft pink, due to a probable inorganic acitvator such as manganese/lead. The dark inclusions are small marcasite crystals. The main crystal in the photograph is approximately 13 mm in length.