Causes of colour and fluorescence in speleothems

Speleothems fluoresce, when illuminated with UV light, between 410 and 460 nm. In this study, we attempted to determine the nature of the fluorophores, thought to be either trace elements or organic matter trapped in the calcite. Fluorescence of solid speleothems and organic species extracted from the calcite were measured to quantify their contribution to the observed fluorescence of the speleothems. All speleothems and extracts gave similar …