^70 



a dark colour. Those of them who are experienced 

 are scarcely ever deceived in this ore, and whenever 

 they strike upon a new vein can nearly determine by 

 the eye the quantity of silver which it will yield. 

 This ore presents three very distinct varieties, though 

 differing but little in appearance. The ñrst, called 

 neFrillo. resembles the scoria of iron, and affords no 

 apparent indication of silver. The second, the rossi- 

 claro, which is distinct from the red silver ore, yields 

 a red powder when filed ; it is very rich although 

 its external appearance is not promising. The third, 

 the piombo ronca, is the richest of all ; as it is mine- 

 ralized with a very small quantity of sulphur, it is 

 much more easily separated than the others, which 

 require a more laborious and complicated operation. 



These three varieties of ore are obtained from the 

 mine of Uspallata, the largest and richest of any of 

 the silver mines in Chili. It is situated upon the 

 eastern mountains of that portion of the Andes which 

 forms a part of the province of Aconcagua. On the 

 top of these mountains is a large plain called Uspallata, 

 of more than seventeen leagues in length and three 

 in breadth, it is watered by a pleasant river and 

 covered with delightful groves, the air is healthy and 

 temperate, and the soil fertile. This plain serves as a 

 base to another more elevated, called Paramtlloy 

 upon which the Andes of the first rank rise to such 

 a height as to be seen distinctly at St. Louis de la 

 Punta, a distance of one hundred and twenty leagues. 

 The ridsre of these immense mountains is a blackish 



o 



clay stone, containing a great number of round stones 



