Can mucus or a solid booger be confused with a cartilage graft or anything else inside my nose?

razny,
Thanks for the question.  Without close inspection and palpation (squeezing) of the booger, it's hard to know for certain whether it is just a booger or something else.  However, I can tell you that it would be really rare for a piece of cartilage graft to come out like this, as they are almost always sutured into place (usually in multiple locations), and a much more common occurrence after nasal surgery of any kind is "nasal crusting" (I'm trying to avoid saying "booger" too much in this response).  Just as you get scabs after you get a cut on your body, you get crusts when you get a cut in your nose.  Extremely solid mucous is a much more likely possibility, and can be helped with nasal saline (though do check with your surgeon prior to use), as hydration can loosen the crusts up.  Good luck avoiding more solid boogers!