All that glitters isn’t just gold
September 22, 2003
One hundred and ten years after silver lost its luster and the Aspen area started withering, another miner has made a big strike in Pitkin County.
It’s not silver or gold that Robert Congdon has struck in the Crystal River Valley. It’s black and brown marble that he contends will have high value for high-end stonework and art.
“This is a pivotal moment in the history of this mine,” he said.
Not all his neighbors are quite as thrilled by his discovery as he is.
Congdon’s mine is located about one mile up Avalanche Creek from Highway 133. It’s about five miles north of Redstone.
He became intrigued in the area in 1982 while camping and poking around the lower flanks of Mount Sopris. Congdon was working as a coal miner near Carbondale in those days.
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He found a band of alabaster, a fine-grained form of gypsum that can be used for interior stonework and sculpture.
Congdon eventually acquired 10 unpatented mining claims, which gave him the mineral rights but allowed the U.S. Forest Service to continue holding ownership of the land. His exploratory dabs into the mountain confirmed his suspicion that the property contained a rich alabaster deposit.
After acquiring a permit for the mine from the Forest Service in 1995 and settling a lawsuit with Pitkin County, Congdon started pulling alabaster out of the mine in 1998. The stone was gray, white and black and sometimes swirled all together.
A study commissioned by Congdon indicated there are 46 million tons of alabaster that can be recovered from his claims.
But that early exploration of the mine turned up results even more intriguing. It confirmed there were also veins of black and brown marble.
Congdon said he believed as early as 1990 that there might be marble veins underground. He found outcrops of high-quality marble on the surface.
He has been pulling alabaster out of the mine since 1998, driving a horizontal shaft into the mountainside. He’s been working toward the marble, but stepped up efforts this summer after securing a contract for a big job. He hopes to secure a second contract soon for a major project.
His crew has extended a development shaft about 140 feet in the last four weeks, but it hasn’t been easy. They use a 22-ton piece of equipment called a “continuous miner” to chew through the rock. It looks like a drill on wheels, with the bit being a rotary saw blade with carbide teeth.
In the last eight years, up to August, that machine required replacement of only four of the carbide teeth. Congdon said he had to replace 40 teeth in just the last four weeks after striking anhydrite, a harder type of alabaster.
Congdon hired Yenter Companies Inc., which is building the four-lane through Snowmass Canyon and also worked in Glenwood Canyon, to blast the development tunnel. Dynamite was used every other day through August and into September to extend the shaft to the marble.
The work paid off last week when they reached a vein of brown marble that Congdon estimated to be 110 feet thick and about 4,000 feet long.
A layer of black marble about 60 feet thick and the same length lies on top of the brown. Congdon said the marble is of a high enough quality that it can be used for everything from tile and window sills to carved sinks and strip stone, like the rock used for the Glenwood Hot Springs.
Mining assessments performed for Congdon indicate that 32 million tons of brown marble and 21 million tons of black marble can be recovered, assuming a recoverability rate of 40 to 50 percent.
Some of it will be left in place when the miners carve rooms and leave pillars standing for stability, he said.
Blasting will continue during the removal of the brown marble, although it will be less noticeable than the blasting used for the development tunnel, according to Congdon. The black marble will be removed by cutting it.
The majority of the marble that is removed will be shipped away for processing.
Scott Condon’s e-mail address is email@example.com.