Simply measure its Eg value and refer the attached paper

I found the attached document, check if it is useful for you. 

The colleagues have given you good literature sources.

You may measure Raman spectra of the your SiC to see which is the dominant allotrope and eventually  if there is a contribution from a different phase.

Refer this article:

Arora, A., Pandey, A., Patel, A. et al. Polytype switching identification in 4H-SiC single crystal grown by PVT. J Mater Sci: Mater Electron 31, 16343–16351 (2020). https://doi.org/10.1007/s10854-020-04184-y