Room-Temperature Phosphorescence and Lifetime of Fossil Resins (Amber) from Dominican Republic, Mexico, Baltic Sea, Myanmar, and Fushun, China

Amber can emit room temperature phosphorescence (RTP) under the well-known 365 nm fluorescence ultraviolet light. This paper is devoted to the phosphorescence study of 20 pieces of amber materials from the Dominican Republic, Mexico, Baltic sea, Myanmar, and Fushun, China. The results show that amber from the same geographic origin has similar shape in phosphorescence spectra.However, the shape of the amber phosphorescence spectra varies depending on their different localities. Burmite (amber from Myanmar) and Fushun amber have a bright yellow phosphorescence with a long lifetime, while the Dominican and Mexican ones are weaker and last shorter. The irradiation of Baltic amber becomes faint or even inert. Phosphorescence spectral Gaussian fitting results suggest an emission maximum near 550 nm in most amber samples. Their phosphorescence lifetime, analyzed through the exponential function fitting, is up to 1 second in Burmite and Fushun samples, shorter in the Dominican and Mexican ones，about 0.230 s, and the shortest in Baltic amber, close to 0.151 s. These variations of phosphorescence lifetime and intensity are related to the relative geological ages of these amber.It indicated that the phosphorescence agent was probably formed during the long geological time. While the anomaly occurred in Baltic amber, the only one found in a sea secondary deposit form, it demonstrated that the terrestrial geological environment these amber preserved has prevented the phosphorescence agent to be deactivated.