TO JOTOTIOH OF GRAND AND GREEH RIVERS. 41 



LOS CERRILLOS. 



Those are a group of hills or small mountains between Santa Fe and the Placer 

 Mountains, on the north side of Galisteo Creek. The highest has an altitude of per- 

 haps a thousand feet; they are somewhat conical in form, and have no distinct linear 

 arrangement West of them are several smaller lulls, extending off toward the Rio 

 Grande, of which one, from its perfect symmetry called the Potato Hill, will probably 

 attract the attention of all who visit that region. The Cerrillos are wholly eruptive in 

 character, mainly trap and trachyte, and by their upheaval seem to have little disturbed 

 the sedimentary plateau on which they rest. They are principally interesting from 

 their minerals, and contain many old mines worked by the Spaniards or Indians. 

 There are found there gold, silver, lead, copper, iron, and turquoise or "chalchuitl." 

 The gold apparently exists in but small quantity; a single locality only, so far as known, 

 having furnished it. It there occurs in a quartz vein, running through a yellow sili- 

 cons trachyte similar to that of the Placer Mountains. The silver is found, in combi- 

 nation with lead and copper, in veins in trachyte. These veins have a direction a little 

 west of north and east of south. By many it is believed that the silver mines of the 

 Cerrillos are very rich, and that they will at some time be a source of great wealth to 

 their possessors. The veins which I examined,- however, are not promising; where 

 exposed they are not rich, and the evidence is wholly wanting that they will prove 

 more so upon further exploration. The most interesting mines of the Cerrillos are 

 those from which the cJialchuitl was taken by the ancient inhabitants of the country. 

 Of these there are several, but one much more extensive than the others — that so fully 

 described by Mr. W. P. Blake, Amer. Jour. Science, Vol. xxv, p. 227. The cfadchuitl 

 occurs in a yellow, porous, trychytic porphyry, in numerous thin and interrupted 

 veins. The mineral is rather abundant, but most of it is of an inferior quality, being 

 of an apple-green color. Pieces of the requisite blue tint, and of sufficient size to form 

 the ear-drops or nose-jewels worn by the Indians, could probably only be obtained by 

 long and laborious excavation; the value which they have always borne attesting their 

 rarity. We found but a single specimen of the requisite purity after some hours' search, 

 and that less than a fourth of an inch in diameter. These mines have undoubtedly 

 been worked for ages; the conical cavity which marks the site of the most extensive 

 one being still a hundred feet in depth by nearly two hundred feet in diameter. Prob- 

 ably no excavation has been made here since the occupation of the country by the 

 Spaniards, but the Pueblo Indians and the Navajoes are still in the habit of visiting the 

 spot and digging in the loose rock thrown out by the ancient miners for fragments 

 which they have overlooked. The chdcliuitl is not unfrequently found about the ruins 

 which are scattered over New Mexico, and the value set upon it by the ancient inhab- 

 itants is still retained by the modern Indians. I have seen ornaments of it worn by 

 the Apaches, Mohaves, the Navajoes and Pueblos, and so highly prized that a fragment 

 of fine quality no larger than the nail of one's little finger and one-eighth of an inch in 

 thickness was regarded as worth a mule or a good horse. The Indians are excellent 

 judges, too, of the quality of the article, discriminating accurately between the different 

 shades of color, and not to be deceived by any base imitation. 

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