History & Geology
Gangue Minerals - What Do They Tell Us?
January 2017 by Chris Ralph
There are a large number of different kinds of gangue minerals, and each of them has its own tale to contribute to the story of the chemistry and geology of a deposit.
The Strange History of the Utica Mine
In the summer of 1854, John Selkirk, a discouraged placer miner who was down on his luck and ready to go back to Massachusetts, tied his mule up in a gulch north of what is now downtown Angel's Camp.
Rare Silver Nuggets And Their Origins
Silver nuggets have been described as “ultra-rare,” “prized” and “unique.” Naturally occurring silver nuggets are rare enough to suggest caution when purchasing. Fakes have reportedly been produced and misrepresented for sale as genuine specimens.
Know Your District
We have to remember that the earliest miners were not geologists, but came from a variety of backgrounds. Their survival depended on finding enough gold so they worked hard and adapted to whatever challenges these new areas presented.
Strategic Metals—Part II
There are literally thousands of abandoned wasterock and ore dumps that dot the United States that could hold many tones of strategic metals.
Mining Pegmatite Deposits
With successively lower temperatures as the water mixture cools, new sets of minerals are formed and many of those stable at a higher degree of heat became subject to alteration as the temperature progressively moved lower.
The Birimian Greenstone Belts of West Africa
A few years ago I had a tremendous opportunity to visit Australia and hunt for gold there. The geology of the gold deposits there was somewhat different from what I was used to here in the US. I learned a lot about greenstone belt gold deposits while prospecting them in person, and it was an amazing trip.
The Wild Rush To Find More Cobalt—Part II
In this second part on cobalt, I will take a look at the various types of cobalt deposits and how you can prospect for them. Who knows—perhaps the next big cobalt strike will be yours.
Subscription Required:
The Bawl Mill
• Ask The Experts: Could you expand on your previous blasting article?
• Ask The Experts: Equipment to break up heavy clay
• Ask The Experts: “Energy” coming from black sand?
• Ask The Experts: Assay problem or recovery problem?
• Legislative and Regulatory Update
• Detecting Strategies for Heavily Forested Areas—Part II
• The Winning Hand
• Early Winter Detecting in the Sierras
• Mining Districts in Montana Get Organized
• Feds Deny Lease Renewals for Minnesota Mine
• Obama Administration Moves to Block Mining Near Yellowstone
• The Perfect Response
• MMAC Update
• Mining Stock Quotes and Mineral & Metal Prices
• Melman on Gold & Silver
Free:
That First Nugget
