Fluorescence Spectral Characteristic of Ambers from Baltic Sea, Dominican Republic, Mexico and Myanmar

Amber was formed millions years ago, through various complicated physical-chemical reactions and subsequent geological process, before they deposited in current depositions. There are many well-known amber mines distributed in Baltic Sea coast region, Dominican Republic, Mexico and Myanmar. Observed under long-wave ultraviolet light (365 nm), amber from these origins present different fluorescent characteristics. In order to gain more fluorescence information and to analyze the detailed fluorescent features among samples from these four regions, we used JASCO FP8500 spectrofluorometer at room temperature, to gain their excitation spectra in 220-500 nm range and emission spectra in 240-750 nm range.The results show that Baltic amber has the strongest emission peak in blue region with the center near 435 nm, which is best excited by 350 nm light. Dominican amber emits three typical narrow peaks at 445 nm, 474 nm and 508 nm. These two samples are optimally excited by 440 nm light, following by 415 nm. The strongest fluorescence center of Mexican amber varies in 420-465 nm under 370 nm excitation. The emission centers of Myanmar appear in visible and ultraviolet region. In visible region, Myanmar has a strong 426 nm emission band, best excited by 375 nm. In ultraviolet region, Myanmar shows two weaker emission peaks near 334 nm and 347 nm optimally excited by 295 nm light.