I wasn't born with a silver spoon in my mouth in Kansas City but I was born with a love for nature and the outdoors in a poor central Kansas farming community.
In the Mosquito Range of central Colorado lies one of the state’s most climbable 14ers, Mt. Sherman (14,043 feet). The common way to access the peak hiking trail is a gravel road leading west from near Fairplay to a parking area at the old Leavick Mill. Since Sherman was only the second 14er that I summited in my early hiking days, that was the route I chose. However, during my next adventure to the peak I wanted to try something different (and more difficult) and that was coming in from the west via Leadville and Iowa Gulch.
For a geologist the upper part of the Iowa Culch trail goes near a number of old mines and one mine that may or may not be somewhat active, but still under claim—the Sherman Mine or the Sherman Tunnel Mine. The mine may be seen from a distance as it is above timberline (12,200+ feet) at the base of a large cirque (Iowa Amphitheater). According to MinDat.org the mine opened in 1968, closed in 1970, reopened in 1975 and then closed again in 1982 and produced around 10 million oz. of silver, and evidently some copper, gold, lead and zinc freed from chalcopyrite, sphalerite, smithsonite, and galena. Like almost all mines in the area the minerals were hosted in a fault-controlled karst system developed in the Mississippian Leadville Formation with mineralization occurring in the Permian.
The Mine is probably best known for producing a rich array of secondary minerals prized by rockhounds including the gangue mineral golden barite, and the carbonates rosasite (copper and zinc), azurite (copper), smithsonite (zinc), aurichalcite (zinc and copper), and cerussite (lead). Azurite and barite specimens were described in a posting on November 20, 2020.
Now two years later I located a small specimen of rosasite and silver that I had sort of not noticed in my collection. Rosasite [(Cu,Zn)2(CO3)(OH)2] is a rather common, interesting carbonate with the copper-zinc ration about 3:2 and forms in the oxidized zone of ore deposits containing copper and zinc. It usually occurs as a botryoidal or spherulitic crust with colors ranging from blue to blue-green to green. The color and the spherulitic nature of the crust make rosasite somewhat easy to identify. The accompanying native silver is a silver white color with some tarnishing to a black (just like “silverware” utensils).
My mountain climbing days are over, but I shall always cherish the numerous expeditions to the many mines in the area and the exhilaration of hiking the nearby 13ers: Mt. Sheridan (13,748), Peerless Mountain (13,348), Horseshoe Mountain (13,898), and Gemini Peak (13,951).
Everyone wants to live on the top of the mountain, but all the happiness and growth occurs while you're climbing it. Andy Rooney
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