THE CULT OF OBSIDIAN
But if the later Nahua immigrants also came to regard these chalchihuitl stones with reverence, at the period of their entrance to the Mexican plateau they paid devotion to a mineral of a very different kind. And this it is which helps us to regard their faith as differing entirely from those other faiths which already flourished in the land. The mineral with which their cult was so closely connected was obsidian, a vitreous natural glass found in the upper volcanic strata of Mexico and northern California, which flakes readily from the core by pressure and gains by mere fracture a razor-like edge of considerable penetrative power. The principal quarry of this volcanic glass was the mountain known as the Cerro de las Navajas (“hill of the knives”) near Timapan, and from this centre the itztli, by which name obsidian was known to the Mexicans, was widely distributed by barter over a very considerable area. There would seem to be proof that this mineral, so suitable for the purposes of the nomadic hunter, was anciently known far to the north of Mexico. The