CdSe1 -xTex nanocrystals (NCs) were obtained by diffusion-limited growth in borosilicate glass and studied by optical absorption, photoluminescence (PL), and Raman spectroscopy. Several Raman-based approaches to determine the NC chemical composition were analyzed. Based on the Raman data, it is shown that for CdSe1 -xTex NCs with intermediate x (0.4  x  0.6) the Te content slightly decreases with the thermal treatment temperature and duration. Confinement-related maxima in the optical absorption spectra of glass-embedded CdSe1 -xTex NCs enable their average size to be estimated, while their smeared appearance reveals a noticeable size dispersion. A rather narrow near-bandgap PL peak with a small Stokes shift dominates in the PL spectra of glass-embedded CdSe1 -xTex NCs, while a lower-energy surfacemediated PL band appears only as a shoulder and vanishes with increasing Te content.