190 
MINERALS YEARBOOK, 1967 
 
tion. The main cause of the decline in these two counties as well as in the
State, was that the Idarado mine, situated in both counties and the largest
source of gold in the State, had a decrease of 10,000 troy ounces from the
1966 output. Although the ore tonnage mined at the Idarado mine was about
the same as that of last year; the gold content was 0.024 troy ounces less
per ton. The only other counties with production exceeding 1,000 troy ounces
were San Juan and Boulder. Nine counties had production between 100 and 1,000
troy ounces; nine had less than 100 troy ounces. 
 
 Iron Ore.—Iron ore production was significantly greater than that
of 1966 mainly because of greater output from the Copper Basin mine of Pitkin
Iron Corp., Pitkin County. Under a lease agreement with Pitkin, the magnetite
ore mined by Morrison-Knudsen Co., Inc., was shipped to the Pueblo steel
plant of CF&I Steel Corp. Brown ore mined from the Iron Springs placer
of Chas. Pfizer & Co., Inc., in San Miguel County was shipped to a company
plant for use as a paint pigment. Theresa B. Robinson shipped brown ore from
a stockpile at the Iron Lode No. 3 mine in San Miguel County for use locally
as a soil additive. 
 Industrial Chemicals Division, Allied Chemical Corp., produced agglomerates
(cinders) from processing pyrites at its sulfuric acid plant in Denver. Containing
65 percent iron, the agglomerates were sold for use in making steel and cement.
However, the output was not considered as mineral production, because the
material was classed as a secondary product. 
 
 Lcad.—Output declined 1,159 tons or 5 percent below that for 1966,
because five of the seven leading sources had reduced production. Two principal
operations with increases in production were the fourth-ranked Brenneman
mine of Standard Metals Corp. in San Juan County which had an output almost
twice that of 1966, and the fifth-ranked Rico Argentine mine of Rico Argentine
Mining Co. in Dolores County, which had production one-third more than the
1966 output. However, the production gains of these two mines were offset
by declines in production from the other five principal operations: the Idarado
mine (first) in Ouray and San Miguel Counties, Sunny- 
side (second) also of Standard Metals Corp. in San Juan County, Eagle (third)
in Eagle County, Emperius (sixth) of Emperius Mining Co. in Mineral County,
and Keystone (seventh) of McFarland & Hullinger in Gunnison County. The
seven leading mines, each with production exceeding 1,000 tons, yielded 93
percent of the State output; the Idarado mine alone accounted for 44 percent.
Twenty-five other mines had lead production ranging from 100 pounds to 369
tons. There were only 32 producing mines, compared with 51 in 1966. 
 Of the 16 counties with production, San Miguel and San Juan, in that order,
were the leading counties with production totaling 13,540 tons of lead, 63
percent of the State output. Output from San Miguel County came from that
part of the Idarado mine in the county and that from San Juan County was
attributed to eight mines. Only five other counties had production exceeding
1,000 tons. 
 The average price of lead declined 1.1 cents, from 15.1 to 14.0 cents per
pound. This drop in price and the decrease in output resulted in a 12-percent
drop in the overall value of lead production. 
 Operated by McFarland & Hullinger, the Keystone mine and mill near Crested
Butte were closed down indefinitely on September 2; however, exploration
work continued. The Keystone operation had been one of the leading base metal
mines in the State since the mine was reopened in 1963. A large quantity
of lead concentrates had to be stockpiled at the mine after the lead smelters
were shut down due to a strike. 
 Asarco and Resurrection Mining Co., a wholly owned subsidi~ry of Newmont
Mining Corp., continued joint venture exploration and development work in
the Irene-Sunday-Hellena area, in the Leadyule district. According to Newmont's
1967 annual report high-grade lead-zinc mineralization with significant silver
and gold values was encountered. An evaluation of the ore potential was being
made with a view to bringing this property into production. 
 
 Manganiferous Ore.—Hotchkiss Mining Corp. shipped stockpiled manganiferous
ore from the Crest mine in Gunnison County; the 20-percent-manganese ore
was used as a soil nutrient in fertilizer.