Deposits of beta and alpha RDX on glass substrates have been examined with optical and Raman microscopy. The measurements reveal significant differences in the morphology and Raman spectra of beta and alpha RDX. Structures that resemble an island, as well as scattered particles, are observed in white light images of beta RDX. Well-defined crystals are observed in white light images of alpha RDX. The spectroscopic signature of these forms of RDX has marked differences in Raman frequencies and relative intensities. The transition from beta to alpha RDX is driven by the amount of RDX deposited. There is a close agreement between measured and calculated vibrational frequencies for beta and gas-phase RDX. A poor correlation is found between measured and predicted Raman intensities and depolarization ratios for beta and gas-phase RDX, respectively. These differences lead us to conclude that the properties of beta and gas phase RDX are markedly different, despite the similarities in the vibrational frequencies.