Rapid outdoor non-destructive detection of organic minerals using a portable Raman spectrometer

摘要

Raman spectral signatures have been obtained for a series of organic minerals using a compact portable Raman instrumentequipped with 785-nm laser excitation. Well-resolved Raman spectra of crystalline salts of carboxylic acids, whewellite andmellite, as well as of the aromatic mineral idrialite were recorded. For comparative purposes, an amorphous fossil resin, balticamber, was also investigated. The results obtained confirm that portable Raman instruments can be considered as excellenttools for field geological applications, including the detection of organic minerals in the frame of outcrops of sedimentary rocksor coal beds. Organic minerals can be added to the list of established biomarkers, including porphyrins, hydrocarbons andorganic acids, which are important for the study with regard to future exobiological missions such as the ESA ExoMars missionto detect the presence of extinct or extant life on Mars.