BATTLE MOUNTAIN MINES, WEST GROUP, AND OUTLYING PROSPECTS. 493 
granite. At the main crosscut on level 6, where two or three minor fissures come into 
the No. 3 from the south, there is a local widening of the ore body to nearly 25 feet. 
The No. 3 vein is not known much above level 6, while below level 8 it joins the Spur 
vein, as already described. The pay shoot is rarely over 100 feet in length. Toward 
the southeast the sheeted zone as a rule passes into a few small and irregular fissures 
which become indistinct before reaching the main east crosscut and can not be 
distinguished from the ordinary jointing of the country rock. Unlike the Spur vein, 
the No. 3 where it cuts through the main phonolite sill 30 or 40 feet below level G 
carries good ore in the phonolite, while in the granite just above and just below the 
sill the ore has proved of little value. The lode is less regular in the phonolite, the 
sheeted zone changing to a number of very irregular fractures containing sylvanite 
or calaverite and pyrite. 
The Montana lode is essentially a phonolite dike along which, particularly along 
its contacts with the granite, there has been a little parallel sheeting. Bunches of 
ore have been stoped at various points along the dike, sometimes on one side, 
sometimes on the other, but rarely within the dike itself. On level 9 a good body of 
ore has recently been found at the point where the Cashen lode meets the Montana 
dike. This ore occurs chiefly on the east side of the dike, partly in the phonolite 
and partly in the granite. As a whole, the ore bodies found along the Montana dike 
have not been important. 
The Cashen lode as exposed on levels 6 and 7 is a sheeted zone in granite 
carrying fairly good ore about 8 inches in width. 
CHARACTER OF ORE. 
The unoxidized ores of the Gold Coin mine are mineralogically simple and owe 
their value to the presence of calaverite, with possibly other tellurides not definitely 
recognized, occurring in narrow fissures with drusy incrustations of quartz and 
fluorite. Metasomatic alteration of the kind that has changed extensive bodies 
of granite into ore in the Ajax and Portland mines is practically absent in the Gold 
Coin mine. At distances greater than a few inches from well-defined fissures the 
granite is barren, or at least does not constitute ore. In parts of the Gold Coin 
and Dorothy veins where the sheeting has been intense the vein consists of a mass 
of crushed granite, quartz, fluorite, and small crystals of pyrite. Such ore frequently 
shows no telluride mineral to the naked eye. Sphalerite, though not an abundant 
constituent of the ore, was noted in the Dorothy vein at the 1,100-foot level. At 
one place near the north end of the mine the Gold Coin vein contains a dark brecci- 
ated streak about 4 inches wide, which is veined with quartz and contains dissem¬ 
inated pyrite and fluorite. The microscope shows this material to consist chiefly 
of granitic fragments, but to contain also some fragments of phonolite. These phono¬ 
lite fragments may have been derived from some phonolite dike cut by the fissure. 
The ore occurring in phonolite exhibits the usual character of ores in this rock— 
small crystals of calaverite occurring with druses of fluorite and quartz in very 
narrow joint fissures. The ore in the Gold Coin mine is not extensively oxidized 
below a depth of 650 feet, though partly oxidized ores are found at a depth of 
J ,000 feet. 
13001 — No. 54—06 - 33 
