4 
GEOLOGY AND GOLD DEPOSITS OF THE CRIPPLE CREEK DISTRICT. 
CHAPTER IV.—GENERAL MINERALOGY OF THE DISTRICT. 
A list of well-established vein minerals includes the following species: 
Calaverite. 
Sylvanite. 
Krennerite. 
Pyrite. 
Molybdenite, 
Sphalerite. 
Galena. 
Stibnite. 
Tetrahedrite. 
Hubnerite. 
Quartz. 
Chalcedony. 
Opal. 
Fluorite. 
Calcite. 
Dolomite. 
Rhodoehrosite, 
Barite. 
Celestite. 
Wavellite. 
Adularia. 
Sericite. 
Roscoelite. 
Among the more important secondary minerals due to oxidation are: 
Gold. Psilomelane. Gypsum. 
Emmonsite. Molybdite. Chalcanthite. 
Limonite. Alunite. Epsomite. 
CHAPTER V.-HISTORY AND TECHNOLOGY OF THE GOLD DEPOSITS. 
Earlier work. —The excellent work of R. A. F. Penrose, jr., was done at a time 
when there were no deep workings in the district. That his results should require 
some slight modification in the light of present facilities for investigation was to 
be expected. 
History of mining development. —Ore found by Robert Womack in Poverty 
Gulch drew E. M. De la Yergne and T. F. Frisbee to the district in December, 1S90. 
They returned in February, 1891, and recorded the first mining location. On July 
4 of the same year W. S. Stratton located the Washington and Independence claims, 
and in the rapid development of the district that followed the Independence mine 
soon attained great prominence. It was rivaled, however, by the Portland, now 
the largest mine in the district. Two railroads were completed into the district 
in 1893, and a third in 1901. There have been two periods of depression due to 
labor strikes, one in 1894 and another in 1903-4. The most important recent event 
in the history of the district was the opening of the El Paso tunnel in 1903, enabling 
several of the mines to extract ore previously below the water level. 
Production. —The district has produced, to the end of 1905, $124,415,022 in 
gold and 646,193 fine ounces of silver, the maximum production having been reached 
in 1900. 
Mining. —The ore is broken by overhand stoping and is usually hoisted by 
steam through vertical shafts. It is generally screened, the screenings as a rule 
constituting the richest part. The coarse ore is washed and hand sorted. The 
total cost of mining, including development and sorting, is probably nowhere less 
than $8 per ton. 
Sampling .—The district is well provided with sampling works, and through 
these nearly all the ore passes in its course from mine to reduction works. The 
sampling charges, exclusive of freight, range from 60 cents to $1 per ton. 
Processes of reduction.— Probably about one-sixth of the tonnage of ore mined 
at Cripple Creek goes to the smelters at Pueblo and Denver. This is the richest 
ore. The balance of the product is treated in chlorination and cyanide mills at 
