XXI. OBSTDTAX MIXES 



OBSIDIAX, a volcanic glass of veiy diversified characteristics 

 of color and texture, was much utilized by the American 

 aboi-igines in their arts. It is found in vast deposits in the 

 Avestern half of Xorth America, and in Mexico and Central America. 

 The -workings where it was obtained thus far have 

 United states received but meager attention. In 18T8 the writer 



made superficial studies of the remarkable deposits of 

 this material in the Yellowstone Xational Park, especially in Obsidian 

 Canyon, where cliffs of black, rudely columnar glass rise to the height 

 of 100 feet or more (fig. 91).^ The refuse of aboriginal operations 

 observed at a number of points indicate the manufacture of the usual 

 varieties of chijiped implements. It is surmised that the aborigines 

 probably worked the deposits of obsidian at many points in the 

 volcanic area of the Yellowstone and Snake Eiver Valleys. 



Obsidian was worked somewhat extensively in the mountains of 

 northern Xew Mexico, in Xevada, and Arizona, and the Pacific 

 States are exceedingly rich in this material, and, although no impor- 

 tant quarries have been located, there can be little question that such 

 exist. Among the most remarkable chipped implements in America, 

 and in the world for that matter, are the obsidian knives of Cali- 

 fornia, the largest of which are upward of oO inches in length and 

 at the same time are of remarkable symmetry and beauty of finish 

 (fig. U'2). It is an especially noteworthy fact that the art of working 

 obsidian is practiced successfully as a matter of gain to-day by cer- 

 tain California Indians. A lay-figure group, intended to illustrate 

 the working of obsidian by the ancient Californians and constructed 

 under the writer's supervision for the San Diego Exposition, is 

 shown in figure 93. 



Obsidian was quarried extensively in Mexico, and the best known 

 mines are found in the State of Hidalgo, about 12 

 Mexico miles northeast of the city of Pachuca, on the 



mountain known as Sierra de las Xavajas, the 

 " Mountain of the Knives." It was the writer's good fortune to visit 

 this mountain in 1899. The journey from the City of Mexico was 

 made in company with Prof. G. K. Gilbert, and the trip over the 



1 Holmes, Notes on an Extensive Deposit of Obsidian in tlie Yellowstone National 

 Park, p. 247. 



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