It could have been 4-HO-DMT (psilocin) in powder form, or it could have been an RC, there's really no way for you to tell without sending some of the mystery substance off to a lab for testing.
If you want more information about where/how you can send it off to a lab, feel free to ask, but ID discussion is not allowed, and apparently this thread never got closed before, but I'm going to do that now. If you want to discuss oral consumption of 4-HO-DMT in pills, visit the 4-HO-DMT Thread