Tuesday, August 8, 2023

HINSDALITE & FLEECED AT THE GOLDEN FLEECE MINE

 


Golden Fleece Mine, Hinsdale County, Colorado. 2018 Photo by Jeffrey Beall, CC BY 4.0 <https://creativecommons.org/licenses/by/4.0>, via Wikimedia Commons.

Back country enthusiasts in Colorado are aware of Otto Mears and his road building (mostly toll roads) experiences in the high mountains in the southwestern part  of the state, especially in the San Juans. For example, he constructed the high mountain highway connecting Silverton to Ouray over Red Mountain Pass, and the Leadville Road over Poncha Pass. He also was into building several narrow-gauge railroads to access mining districts including the Rio Grande Southern Railway from Durango to Ridgeway over Lizard Head Pass. And last but not least, he was the mover and shaker in getting the dome of the Colorado Capitol gilded with 200 ounces of gold.

At any rate, a fellow road builder by the name of Enos Hotchkiss hooked up with Mears in ~1874 to construct a road from Saguache to Lake City. Along the way, near the current Lake San Cristobal, Hotchkiss noticed some interesting ore rocks and filed a claim, the Hotchkiss Claim. It turns out that Hotchkiss had a good eye for ore, and the Hotchkiss Mine was off and running. Unfortunately, in late 1876 poor ole Enos was badly injured as he fell several feet down a shaft. The Mine was idled for several months until new owners appeared and renamed the Hotchkiss to the Golden Fleece Mine. Gold, silver, and lead with minor copper and zinc were the major metals produced. The Mine also stimulated the economy in Lake City as numerous other mines went into production and a rail spur reached Lake City in 1889. The Lake City Mining District was booming. The Golden Fleece shipped one rail car containing ~$50,000 of high-grade ore while in 1895 the Black Crook Mine sent out ~$200,000 of pretty decent ore.  In early December the Golden Fleece was listed on the Colorado Springs Mining Exchange [Golden Fleece Mining and Milling Company (Iowa)] opening at $1.10 per share and closing at $1.30. The Company purchased the Colorado City Mine in Cripple Creek and also had an interest (owned?) producing gold mine(s) in Georgetown. But that was it, the boom was soon off, and the bust hit the entire Lake City Mining District. Evidently, “bad luck” prevented the miners from finding new veins. Although the mines in the Lake City District were exhausted all was not lost as the Golden Fleece had produced almost a million and a half dollars of gold (today’s price? )and silver before shutting down, and restarting, and shutting down, etc. In 1897 the shares were going for $.56, in 1900 $.26 and everything ended in 1903 at $.06. Well, sort of ended as businesses piddled around with the mine until about 1920.

The Golden Fleece was not helped by the fact that during the boom years a “systematic robbery by professional thieves” had siphoned off about half of the gold output. As best I can determine the “professionals” worked in the mines and simply high graded the ore and took it out in their “lunchboxes.” Then the Pinkerton National Detective Agency caught up with the bad guys. [Check out the newspaper articles in References Cited section].

MinDat (August, 2023) lists 46 valid minerals known from the Golden Fleece Mine including native gold and several gold bearing tellurides, various ore minerals: several silver bearing minerals, galena (lead), covellite (copper), bismuth (bismuthinite), sphalerite (zinc), etc. In addition, there are rare minerals such as mawsonite (copper-iron-tin sulfide) and melonite (nickel telluride. See previous post) and others. The Golden Fleece is the Type Locality for one mineral, hinsdalite, named after Hinsdale County, Colorado, home of the Golden Fleece.. The County is one of the most remote in the lower U.S. and a mecca for mountain climbers with five fourteeners and several thirteeners. Colorado 149 from Smith Fork north to Powderhorn through Creede and Lake City is one of the most majestic highways in the country.

Green hinsdalite from the Golden Fleece Mine. Width FOV ~3mm.
 

Hinsdalite [PbAl3(PO4)(SO4)(OH)6] is a hydroxy (OH) phosphate (PO4) – sulfate (SO4) and some mineralogists also stick in strontium as another cation with lead and aluminum as the mineral contains almost 4% of this element (see Webmineral.com). Hinsdalite contains two oxyanions, sulfate and phosphate, a rather unusual occurrence. Although some specimens show crude rhombohedral crystals or hexagonal plates my specimen from the dump at Golden Fleece is extremely small but does have a botryoidal green crust of hinsdalite. There are other tiny areas of porcelaneous green masses, but crystals seem to be absent. The botryoids have a greasy luster, seem to be translucent, and a measured hardness of ~4.5 (Mohs). Hinsdalite is a secondary mineral in the oxidized zones of polymetallic  (especially sulfides and tetrahedrite) ores. It is forms a solid solution series with, and is visually indistinguishable from, plumbogummite [PbAl3(PO4)(PO3OH)(OH)6]  except by electronic gizmos determining the phosphorous-sulfur ratio (Frost and others, 2011). MinDat does not list plumbogummite as being present at the Golden Fleece, hence the use of hinsdalite.

I have noted in other posts that the phosphate anion (PO4) and the arsenate anion (AsO4) are of similar size and chemical makeup and may substitute for each other. Hinsdalite with PO4  is the phosphate analogue of hidalgoite [PbAl3(AsO4)(SO4)(OH)6]. Van Wambeke (1971) believed that hinsdalite in a rock unit or erosional detritus  may indicate the presence of valuable ore minerals.         


 

 

Spherical encrustation of tan to orange hidalgoite composed of microcrystals; each sphere ranges from .3-.5 mm. Specimen is from Gold Hill, Utah.

 REFERENCES CITED

Frost, R.L., S.J. Palmer, and Yunfei Xi, 2011, A vibrational spectroscopic study of the mineral hinsdalite (Pb,Sr)Al3(PO4)(SO4)(OH)6: Journal of Molecular Structure, vol. 1001, Issues 1-3.

Van Wambeke, L., 1971, Hinsdalite and corkite: Indicator minerals in central Africa: Mineral Deposita vol. 6.

The Golden Fleece Robbery

 The New York Times, June 16, 1895, p. 1: Fortunes in Pilfered Mine Washings; Golden Fleece Company Loser - Thousands to Spend to Punish Thieves.

 San Francisco Call, June 15, 1895, p. 4: Robbery of a Rich Mine, Daring Theft of Ore at the Golden Fleece in Colorado.

 The New York Times, June 17, 1895, p. 1: Colorado's Mine Thieves. Probable They Have Stolen Ore Worth Millions Of Dollars. Have Been Operating Ten Years. No Doubt They Have an Organization and Careful Methods of Robbing — Many Mine Owners Suffer.

Siringo, Charles A.: A Cowboy Detective: A true story of twenty-two years with a world-famous detective agency, Chicago : W. B. Chonkey Co., 1912; published in several other reprinted editions.

 Sunday Herald (Syracuse, NY), June 23, 1895, p. 6: ROBBING A MINE. Systematic Fleecing of Ore of the Richest Gold Properties

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