CENTEAL AND EASTEEN NEVADA. 351 



The ores generally consist of rich silver-bearing minerals, comprising 

 pyragyrite, proustite, stephanite, polybasite, tetrahedrite, argentiferous galena, 

 zincblende which is believed to carry silver, copper jjyrites, and iron pyrites. 

 The proportions in which these components are mingled vary a good deal, 

 certain portions of some veins carrying the richer silver minerals in such abun- 

 dance as to make the average value of the ore several hundred dollars per ton 

 throughout entire bodies of large extent, while in others the baser metals 

 predominate to that degree that the average value of the ore is too small to 

 pay for working. The gangue is chiefly quartz, manganese spar, which is 

 very characteristic, and calcspar. Near the surface the ores are usually 

 decomposed and altered, carrying hornsilver, and the chlorides, oxides, and 

 some salts of the associated metals ; they are locally known under the general 

 term of " chloride," and, being easily worked, yielded, in early days, a large 

 product with comparatively simple means of extraction. In depth the ores 

 have suffered less change; they occur in compact form, and often present in 

 their method of arrangement or deposit in the vein a beautifully regular and 

 banded structure. 



Lander Hill has always been tbe most important and productive part of 

 the whole district. A very large proportion of all the bullion produced by 

 the Austin mines has come from within a small area on the southern slope of 

 that hill; and during the last two or three years, since the abatement of the 

 prospecting fever, the mining work of the district, with one or two exceptions, 

 has been chiefly confined to that locality. 



The outcrops on the liillside are very numerous, and many locations have 

 been made, some within ten or twenty feet of each other. Some of these out- 

 crops have been proved by actual development to be well defined and persistent 

 fissures; others are probably mere seams or branches that pinch out or unite 

 with stronger veins in depth; and that many must disappear in this manner 

 seems apparent from the fact that the number of veins or fissures cut in the 

 deeper crosscuts and shafts, in various parts of the hill, bear a very small pro- 

 portion to the number of outcrops at the surface in their immediate vicinity, 

 which, if persistent, would appear below. 



The developments on Lander Hill show that within this mineral belt, 



