Note 11 — Chapter IV · TACUBAYA. PACHUCA. REAL DEL MONTE.

The book-name for obsidian is itztli, a word which seems to mean originally “sharp thing, knife,” and thence to have been applied to the material knives are made of. Obsidian was also called itztetl, knife-stone. But no Indian to whom I spoke on the subject would ever acknowledge the existence of such a word as itztli for obsidian, but insisted that it was called bizcli, which is apparently the corrupt modern pronunciation of another old name for the same mineral, petztli, shiny-stone.