Custer weekly chronicle. [volume] (Custer City, S.D.) 1890-1931, 1896-02-22

give wide berth to the quack assayer
who has some particular method of his
own, or what he is pleased to call q
chemical analysis" process, which he
claims is the only true method for de-
terDining the value Of an ore.
These frauds are scattered all oyer
the country and are often the cause OF
no little disappointment 10 the honest
prospector. 1t sometimes happens that
a prospector is so far away from reli-
able assayer that it is impossible for
him to ascertain whether the ore con-
tains gold or not when the presence OF
tellurium is suspected.
"A very simple test, requiring no par
ticulsr skill, can be used 10 determine
whether or not tellurlum is present in
an oxidized form for if il is found that
tellurium is present, il is pretty safe 10
presume that gold accompanies ii. This
test which / will give here, is one which
recommended in a paper read before
the Colorado Scientific Society some two
years ago, and was the result OF some in
ysstigations on oxidized Cripple Creek
ores.
Fifty grammes of the fine pulp ore
are treated with dilute hydrochloric
acid, consisting Of equal parts of acid
and water. The mixture is heated Il
boiling and filtered, and 10 the filtrate
is added solution of stannous chloride
The tellurium, if present, will immedl'
ately be precipitated in black fiocu
lent form as metallic tellurium; If iti
quantity is small it ID best TO heat the
solution, which aids the separation. II
must, however, be remembered thai
this test is only applicable 10 ores which
contain the tellurium in an oxidized
form, and is Of no value in other cases
Below the water line the tellurides
proper occur, and in Cripple Greek they
are represented by the minerals sylvan
ite and calaverite. Sylvanite is as
white and lustrous as pure silver, and
contains, when pure, about twenty
seven per cent gold. Calaverite has a
slight yellow appearance, resembling
somewhat pale variety ofiron pyrites
and contains about forty per cent ofgold
The presence Of tellurium does not
in every case prove the existence oI
gold, but think it may be said to be
the rule at Cripple Creek. Boulder
county has produced what is termed
native tellurium and telluride OF lead
tsltaite which contain no gold what
ever, and ! have known Of the occur.
renee of telluride of bismuth (tetrsdy
mite in Montana containing little or nc
gold. but these samples are rare. The
occurrence of fluorits OF purple ol
amythestine color. SO characteristic o.
Cripple Creek ores, may be regarded al
a favorable indication of the coexist
ance Of tellurides. This peculiar asso
citation is well marked in ether districts
such as Boulder county, Colorado, anC
| in the tellurum gold ores Of South Da
kota, so that il indicates some sort o
close kinship between the two minerall
or rather that they owe their existence
to some one common origin.
"Ths distribution Of telurium is in
finitely more extensive than is general!
supposed, but its importance as min
eralizer Of gold has not been recognized
! 10 any great extent in connection will
important gold deposits
Careful investigation has proved it
existence in localities where its pres
encs had not hitherto been suspected
Recent examinations have shown tha
| the gold deposits in the so-called Pots
| dam sandstone of South Dakota, AM
1 that of the famous Mercur mime in Ctal
owe their Importance TO gold in comb
nation with tslluriun, 30 that this ell,
ment which, until recently. has bee
regarded as occurring in few localitie
may claim far more intimate relation
ship with gold than was ever sur
| posed -