The Goldfield news. [volume] (Goldfield, Nev.) 1904-1911, 1909-06-12

.,lv overlooked by the prospector
;rd;cation of gold values in that
vicinity, and the ''sign-post'' OF riches
no PASSED unheeded.
An especially enlightening article on
,h;s subject has been written by >.
v,l,ev Lewis, a noted mining geologist
- New York, for the Mining and Engl-
,osrinc Journal. A supplemental section
= ,b;s treatise has been prepared by IL.
r Gage, chemist of the geoiogicai
,n,vev of New Jersey, giving simple
.,,d effective methods for quaiitive de-
termination in the field. These articles
arc so important to the prospectors
and mining men of Nevada that The
yous gives them space in the hope that
!, NAV serve the purpose of guiding
the prospector in his search for other
coldfelds. The article by Mr.. Lewis
follows:
..Ip the Goldfeld district ~alunite is
a. abundant and so generally asso-
eia,ed with the intense alteration ac-
eompanying ore deposition that it must
no looked upon as N OF the most
Characteristic minerals of the gold de-
nosits.u With this announcement
Ransome not only added a new type
TO the geology of ore deposits, but
noipted out a most promising new field
for exploitation. The ~prospector, how
ever, has not rushed in to possess the
new land. He has rather roamed about
bIindly over vast areas of desert AMI
mountain in the hope that somewhere,
somehow. he would stumble upon the
coveted treasure; but no practical
means has been put into his hand fo-
recognizing the ore he seeks.
There is gratifying evidence that the
scientific prospector, the mining geo-
logist. is availing himself of the new
knowledge to more purpose; but the
vast area that may possibly bear this
type of ore is too much for the few
scientific men who are in the field. If
the present generation or the next is
to realize in any large degree the
Possibilities that have been opened up,
we must enlist the larger army of
practical mining men.
The Prospector's Dilemma.
The prospeetor who knows his por-
phyry, his limestone, and the honey
eombed rusty gossan that bespcaks the
deeperlying sulphurets has been taught
by long experience to disregard all
manner of whitish or grayish or clean
looking rock. The big mines that he
knows have been opened on very uif-
ferent looking lodges, and only a ter
lerfoot would pause for a second look
at the unstained outcrop. To the pros
peetor in the desert all this has now
\ been changed. If he has learned the
lesson of Goldfeld he knows tLat
amazing values have been developed
there in a beautifully white porcelain
like material for all the world like the
most barren porphyry; and now others
are duplicating this Goldfeld expert
enee in far-away corners of the desert,
while vast inviting fields still lie I'M
explored.
| do not mean to say, Of course, that
lron-stained material is not found at
%GOldheld, both on the outcrops n in
the mines, but merely that this is not
necessary or characteristic feature Of
deposits that carry high values.
Under such conditions what is the
prOspector to do? He cannot sink pits
or every ledge, whether rusty or white,
and have assays made all over the face
Of the earth. Besides, the assayer may
miss the main point altogether. There
may not be enough gold in the CROP
ping or in the shallow pit to excite the
mildest interest, but if alunite is there
'he prospector wants to know 1T, what
ever the values, for it is worth while
10 follow it down. o bit and try the
assayer again on the deeper levels. OF
course, alunite does not everywhere
and under all conditions indicate the
presence of gold; neither does rusty
quartz nor any of the various '.indl-
e%a'ions' by which the prospector Is
guided; but the abundance of the min
efai and the eonstancy of it's associa
uon with the ores at Goldfeld, follow
eu now by a similar occurrence in 1
ueS locality, are extremely suggestive
'ha there are large areas in the South
west where geological conditions arr
closely similar.
Characters and Occurrence.
Alunite occurs in hard, white, porce
unlike masses, or in fi~ne-grained con
"ioh life loaf sugar. In the latte
se II ls either firm like marble, or /
NAY be easily crumbled into a snow
'u'e mass resembling pure kaolin an
~~euit to distinguish from it in tn
"ines. At Goldfeld it often has
81 pinkIsh color, while the kaolin
"ue' Sometimes it is found in lttl
DSuare'iooking crystals (rhombohes
sl which form nests in the smaI
f'nihgs OF the rock, but these are rar