Potomac in Montgomery County, Maryland — The American Northeast (Mid-Atlantic)
The Maryland Mine
Chesapeake and Ohio Canal Historical Park
During the Civil War a Union soldier assigned to guard the Great Falls area discovered gold in the quartz rocks in the surrounding hills. After the war, he returned and purchased land from local farmers and began prospecting for gold. While the former soldier and his partners are only known to have found 11 ounces of the precious metal, their find inspired hundreds of men to continue to hunt. Gold fever, dreams of wealth and a better life, caused men to risk everything in search of the elusive ore.
Hoping to succeed where others failed, the Maryland Mine began operations here in 1890 and ran intermittently until 1940.
Location. 38° 59.679′ N, 77° 13.95′ W. Marker is in Potomac, Maryland, in Montgomery County. Marker can be reached from Falls Road. Touch for map. The marker stands along the Goldmine Loop Trail in the C&O National Historical Park at Great Falls,
Other nearby markers. At least 8 other markers are within walking distance of this marker. Great Falls of the Potomac (about 600 feet away, measured in a direct line); The Floods (approx. 0.7 miles away); Mather Gorge (approx. 0.9 miles away in Virginia); Creating a National Park (approx. 0.9 miles away); Washington Aqueduct (approx. 0.9 miles away); Boats Passing By (approx. 0.9 miles away); A Lift Lock (approx. 0.9 miles away); Great Falls Tavern (approx. 0.9 miles away). Touch for a list and map of all markers in Potomac.
Regarding The Maryland Mine. “The gold was recovered by the oldest and easiest known method, Amalgamation, which is carried out by the addition of mercury to the pulp inside the mills at regular intervals. As the specific gravity of gold and mercury is nearly the same; they lag behind to combine and form an amalgam , while the lighter quartz pulp washes out in the tailing pool. The pulp from the stamp mill is washed over a silvered copper plate, brushed over with mercury, to catch the amalgam. The pulp from the ball mill is washed into an impact amalgamator for the same purpose. Large nuggets are recovered inside the stamp mill
The concentrates were so low in values , they were allowed to run off with the tailings. After several weeks run, depending on the grade of ore going thru, the mills were shut down for a general clean-up. The solid amalgam was gathered and retorted , this vaporized mercury passing over from the retort thru a pipe was condensed in water and recovered to be used over again. The remaining gold left in the retort was ready for shipment to the mint in the form of a light yellow porous mass, called retort sponge.
Gold is nearly always alloyed with silver, which sometimes amounts to one third of the metal. The proportions of silver in Maryland gold is much less than is usually found in native gold. One mint receipt for $1,090.63 shows $.46 in silver. Another shows gold from hand mortored nuggets to run 977.3/4 fine.” — Edgar T. Englalls, 1960, The Discovery of Gold at Great Falls, Maryland, 1861.
Categories. • Industry & Commerce • Man-Made Features •
Credits. This page was last revised on May 9, 2017. This page originally submitted on April 27, 2017, by Allen C. Browne of Silver Spring, Maryland. This page has been viewed 152 times since then and 29 times this year. Last updated on May 9, 2017, by Darrel Ricketts of Silver Spring, Maryland. Photos: 1, 2, 3, 4, 5, 6. submitted on April 27, 2017, by Allen C. Browne of Silver Spring, Maryland. 7, 8, 9. submitted on April 28, 2017, by Allen C. Browne of Silver Spring, Maryland. • Bill Pfingsten was the editor who published this page.