o \tp> 'in >>' and value >f the --res. 
171 
is probably some silver mineral present, possibly tetrahedrite. which is known to 
occur at the El Paso—a surplus of silver may belong to this, and the gold and 
tellurium, with some silver, would combine to form calaverite without free gold. 
As is well known from other mining districts, especially Kaigoorlie. free gold may 
occur in considerable quantities with tellurides. 
The Cripple Creek ores, as a rule, contain very little silver, the averse propor¬ 
tion being about 1 ounce of silver to 10 ounces of g Id. In the Portland and Strat¬ 
ton's Independence mines the proportion is very much less, the silver from the 
Portland in 1901 amount ins: t only 2.4 ounces for each It ounces :f : Id. Rich 
parcels of gold ores often contain a surprisingly small quantity of silver. In the 
shoot on the 245-foot level in the W. P. H. mine even the richest ore. valued at 
several thousand dollars per ton. contained but a few ounces of silver per ton. The 
“fines from the El Paso mine analyzed by Hillebrand and Alien/ which were 
practically free from oxidation, contained from 2.19 to 3.00 ounces silver against 
14.53 to 19.63 ounces gold. In the Blue Bird. Doctor-Jackpot. Conundrum. Pointer, 
and other mines containing n -table am. tints of tetrahe* irite or ral-na :he : r -por¬ 
tion of silver rises considerably above the average. Very rarely small lots f ore 
contain a higher value in silver than in gold. A shipment of 1.000 pounds of gray 
copper ore from the Accident mine contained 2.500 ounces silver and 25 ounces 
gold per tt>n. Somewhat similar silver ore occurred in the Pointer mine. A recent 
shipment from the Red Spruce min e on Gold Hill is stated to have contained 
50 ounces of silver and $5 in gold per tonb 
That the average tenor of the ores of Cripple Creek is decreasing: somewhat is 
an unquestionable fact. Penrose says that the average value : ill re shipper up 
to 1S94 would be between $50 and $85 per ton. The Mint report for 1S97 p. 122 
states that the average value lies between $35 and $40 per ton. while in me same 
report for 1899 (p. 99) $45 is given as the average value of the ore. At the present 
rime it is from $3‘! to $4 oer ton. The early figures of IS94 may be lisregardei. 
since high expenses and excessive freight prohibited the snipping : 1* w-graae re. 
The Portland data show a very decided decrease, as f- 11 ws: 
Tenor faSd arejfrvm PorLxnd mime. 
Per son. 
Ber He. 
1SS4.. 
.. $71.00 
1900 ... 
.£36 00 
lv 
... 5L 00 
1908.... 
. 29.0*0 
1047 
... 60.00 
19*34.. 
_ 36.92 
1900... 
... 30.00 
19*35__ 
.. 23.60 
A value of $30 may represent the average of some >5 the largest mines, but 
most of the smaller ones and many of the large ncs 'hip ore much richer man Has. 
Some of the decrease is unquestionably caused by lowered operating and reduction 
expense', and it is doubtful whether more than a small fraction should be barge 1 
to the actual falling off of values in depth. If this really takes place, ii is prob¬ 
able due to a slightly lower tenor in the unoxidized ores than in these which Lave 
been subjected to oxidation. 
* BsiL IT. S- CeoL Sarwey No. p. K 
i V — tr.i Set. Press. Saz Fnmeiscr Oct.Oer L. 
- rjciesirii x- - Rape. U- S- »>roi. Srurr--. pc. — HO. p. . 2. 
