Understanding Hard Rock Mining: Terms and Methods—Part I
June 2004 by Chris RalphWhile most small-scale prospectors and miners focus their energies on placer deposits, most large mining companies put their efforts primarily into hard rock mining. Although many miners may see these as two separate worlds that can never meet, a better understanding of hard rock mining for small operators can be very helpful in many ways.
Excerpts from California Mining Journal, our original title, published 50 years ago this month.
Gold in clastic black shale
The Little Rocky Mountains are a group of wooded hills, 10 miles long and 8 miles wide, which form an island in the Great Plains of north-central Montana. They rise to 5,708 feet, 2,000 feet above the surrounding plains.
Although it is now known that Mount Diablo, located in Contra Costa County in the East Bay region of the San Francisco Bay Area, was the site of the largest coal mining operation in the state during the last half of the 19th century... this majestic focal point... also was the source of other minerals.
The black sand was loaded with mercury from the river, but there wasn’t enough to pick up all the fines. We took out the amalgam and had to suction up the remaining fine gold.
Saturday came and it looked to have the makings of a dreary, misty day. Undaunted, I loaded my truck with my sluice, buckets and gear, and headed for the claim.
The Bawl Mill • Higher Copper Price Brings Hope, Jobs • Zeballos Gold Camp, British Columbia • Agreement Allows Pogo Mine to Resume Construction • Treasure Hawk Mine Back in Action • Oregon Dredgers Receive Threats From Environmentalists • Mood at Calgary Conference is Subdued, But Optomistic • Reinventing the Wheel—The Infinity-Jet • Company Notes • Endangered Species Act is a Mess • Placer Platinum • Here Come the MineBots • Agency Gives Initial Backing to Kensington Mine • Mining Stock Quotes and Mineral & Metal Prices • Looking Back • Melman on Gold & Silver • Brits Thwart Robbery of Gold and Cash