Abstract: The gemmological characteristics, microtopography and IR spectra of jet samples from coal measure strata in Fushun, Liaoning Province, are studied by using the conventional gemmological methods, XRD, ESEM and FTIR．The results show that the samples mainly consist of amorphous resinite and humus, where the microtopography of the organic constituent is irregular squamose groups．There are functional groups in the samples such as OH, CH₂, CH₃, C＝O, C－O, Si－O and C－H, which have specific spectra at 3390, 2959, 2930, 2857cm^-1．The jet samples are more compact than the coal samples because the honeycomb-like apertures of coal are filled with a large number of resinite and gelatin for gelatination resulting in the changes of loose structure．