DESCRIPTIONS OF MINES. 
127 
and galena. Much of the ore is of good grade, the samples assayed by Dr. Yeates in his 
report on the gold deposits of Georgia containing from .$12 to $15 per ton. The average is, 
however, probably less than this. Most of the gold in this vein is said to appear as native 
metal in the reddish-brown garnets and a specimen obtained substantiates this statement. 
It is very clear that the coarse-grained mixture of garnet and mica is the result of the 
alteration of the schist and its study presents several interesting features. Sections of 
the quartz show normal, hypidiomorphic, coarse-grained structure, the grains exhibiting 
no optical disturbance. Fluid inclusions with gas bubble and in some instances solid 
transparent particles also are very abundant. Embedded in the quartz lie streaks of 
aggregates of common green hornblende, usually in irregularly lath-like grains molded 
by the outlines of the quartz grains; in places radial bunches of hornblende prisms also 
project into the quartz. Associated with the hornblende are granular aggregates of a 
mineral which corresponds well to apatite; locally these are also wholly embedded in quartz. 
There are also small foils of muscovite and isolated similar forms of biotite. Anhedrons 
of pale-red garnet are inclosed in the quartz or conform to the outlines of the quartz grains. 
In the hornblende lie embedded 
scattered grains of pyrite and more 
abundant ilmenite. A few imper- 
fect crystals of ilmenite are con- 
tained in the quartz grains, between 
which a little calcite also appears. 
Other sections made from tne 
polished specimen show large round- 
ed crystals of garnet, with a few 
inclusions of green mica. The gar- 
nets are contained in a coarse ag- 
gregate of straight mica foils, with 
a pleochroism varying from pale 
green to deep leek green. The 
exact mineralogical position of this 
mica has not been ascertained. 
Veins similar to the Lockhart are 
mined at the Findley and the 
McAfee mines. In the McAfee the 
garnets are said to be smaller than 
in the Lockhart, but tbey also con- 
tain native gold. 
Quartz 
Mica— garnet 
rock 
Schist 
-Diagram showing structure of Lockhart vein. 
BENNING MINE. 
The Benning mine is situated 1 mile northeast of Dahlonega, on Yahoola River. The 
developments are limited and consist chiefly of a large incline driven on a wide quartz lens 
in the mica schist within 25 feet of the granite contact, but parts of the vein are also con- 
tained in granitic dikes. The country rock is here a dark-gray glistening mica schist con- 
sisting of a quartz mosaic without much feldspar; in this are embedded dirty-brown sharply 
outlined foils of biotite, many of them small and straight ; a smaller amount of muscovite 
is present in similar foils. There are also a few grains of calcite, inclosing some mosaic, 
and a few foils of chlorite, probably not derived from the biotite. Magnetite is distributed 
throughout rather abundantly and there are a few grains of pyrite and pyrrhotite. The 
schist also contains a few large crystals of garnet inclosing smaller masses of mosaic; a 
few prisms of tourmaline were noted. The whole structure is typically crystalloblastic. 
Along some small stringers of quartz to the left of the granitic dike garnets have devel- 
oped abundantly, but whether this quartz is of the same origin as the gold-quartz veins 
or represents a local quartz facies of the granite could not be definitely ascertained. 
The quartz lenses which range up to several feet in width consist of coarse normal vein 
