Hydrocarbon composition of Russian amber from the Voznovo lignite deposit and Sakhalin Island

Amber of different color and fluorescence has recently been found in a lignite seam in the Zerkal'nenskaya depression, Primorsky Krai, Russia. In this deposit, the amber is associated with abundant charcoal and fusain fragments in the host rocks. Beside three composite samples of different color from the lignite and one composite amber sample from the Sakhalin Island has been included in this study for comparison. Based on previous fluorescence and fluorescence excitation measurements, the blue glow of amber has been related to the fluorescent aromatic hydrocarbon perylene, although FFIR study of the Russian blue amber has not found any distinct signature of this compound. The present analyses using gas chromatography-mass spectrometry have also identified no perylene in any of the four Russian amber samples. The hydrocarbon fractions of the extractable organic matter from the ambers are dominated by C-18 to C-20 diterpenoids of the labdane, abietane, pimarane, phyllocladane and kaurane types. Their biomarker composition is consistent with the proposed origin from gymnosperms of the families Pinaceae, Cupressaceae, and/or Taxodiacceae. The cause for the blue amber glow could not be clarified based on the commonly used methods of hydrocarbon composition study. (C) 2016 Published by Elsevier B.V.