This chert knife represents the god Tecpatl who protects the day and also has a day in the Miztec (Aztec) calendar dedicated to it. This calendar day is one of trials and tribulations in which the character of people is tested.
This piece’s teeth and cornea are likely made of shell. The knife looks to have once been stuck somewhere so that it sat vertical, as a bit of cement-like substance is still seen at its base.
Found: Templo Mayor, Ciudad de Mexico