Geology and stories from the past
Can You Recognize Valuable Ores?
August 2016
The process of recognizing ores all starts with being able to recognize some basic minerals and knowing what hard rock ore looks like in the districts where you prospect.
The process of recognizing ores all starts with being able to recognize some basic minerals and knowing what hard rock ore looks like in the districts where you prospect.
Exploring A Historic Lode Mine
August 2016
Climbing up the debris, I pointed my flashlight up a shaft ascending straight up as far as my light would shine. It was the stope of the pay shoot leading to the old tunnel above!
Climbing up the debris, I pointed my flashlight up a shaft ascending straight up as far as my light would shine. It was the stope of the pay shoot leading to the old tunnel above!
The Heavy Minerals in Your Concentrates
June 2016
The fact that mineral deposits can contribute specific types of heavy minerals is why the analysis of the heavy mineral concentrates in the streams of an area can be an important prospecting technique for finding undiscovered mineral deposits.
The fact that mineral deposits can contribute specific types of heavy minerals is why the analysis of the heavy mineral concentrates in the streams of an area can be an important prospecting technique for finding undiscovered mineral deposits.
Critical Metals: Antimony
June 2016
I’ve been taking a look at the mining and uses of a number of critical metals in series of articles, and it’s time to take a look at antimony.
I’ve been taking a look at the mining and uses of a number of critical metals in series of articles, and it’s time to take a look at antimony.
Nevada's Silver City Gold District -- Part II
May 2016...this district has had a continuous life of gold mining and milling that spans 150 plus years, and it appears that it will keep pressing on for many more years of production.
The Tombstone Silver-Lead District, Arizona
April 2016
In 1877, a prospector named Ed Schieffelin discovered silver in “the middle of nowhere” and staked two claims: “Tumbstone” and “Graveyard.” Soon a town and mining district were organized and acquired the name “Tombstone” after making a spelling correction.
In 1877, a prospector named Ed Schieffelin discovered silver in “the middle of nowhere” and staked two claims: “Tumbstone” and “Graveyard.” Soon a town and mining district were organized and acquired the name “Tombstone” after making a spelling correction.
Enrichment of Mineral Deposits by Weathering—Part II
April 2016
While both zinc and lead deposits also are enriched by the surface weathering process, in part two we will look at the enrichment process for copper and also gold deposits, and at the interpretation of leached outcrops to figure how rich the concentrated deposits below them may be.
While both zinc and lead deposits also are enriched by the surface weathering process, in part two we will look at the enrichment process for copper and also gold deposits, and at the interpretation of leached outcrops to figure how rich the concentrated deposits below them may be.
The Bawl Mill
March 2016
• Do as I say, not as I do...
• By the numbers...
• Do as I say, not as I do...
• By the numbers...
Green Valley Gold District, Payson, Arizona
March 2016
Most gold-bearing quartz veins found in the district were fracture fillings in faults enclosed by crushed quartz zones along their margins. Since the host rocks were often extensively weathered, portions of the veins stood out as positive, resistant outcrops. The gold-bearing veins ranged from a few inches wide to the vein at the Gowan mine that was as much as 12 feet wide.
Most gold-bearing quartz veins found in the district were fracture fillings in faults enclosed by crushed quartz zones along their margins. Since the host rocks were often extensively weathered, portions of the veins stood out as positive, resistant outcrops. The gold-bearing veins ranged from a few inches wide to the vein at the Gowan mine that was as much as 12 feet wide. 
Nevada's Silver City Gold District—Part I
March 2016
The name Silver City is quite ironic as it doesn’t really fit the area’s metal production. The area encompassing the Silver City district is a great, stand-alone gold district, where the production value of gold has been much more than that of silver. Since the initial discovery of gold-bearing veins in the mid-1850s, the area has been a center of continuous small and large-scale gold production.
The name Silver City is quite ironic as it doesn’t really fit the area’s metal production. The area encompassing the Silver City district is a great, stand-alone gold district, where the production value of gold has been much more than that of silver. Since the initial discovery of gold-bearing veins in the mid-1850s, the area has been a center of continuous small and large-scale gold production.Enrichment of Mineral Deposits by Weathering—Part I
March 2016
The exact minerals formed in the concentrated supergene deposits depends much on the type of country rock around the deposit and the chemistry of the deposit itself, but if conditions are right, this process will form some rich patches of bonanza ore, in some places valued at thousands of dollars to the ton.
The exact minerals formed in the concentrated supergene deposits depends much on the type of country rock around the deposit and the chemistry of the deposit itself, but if conditions are right, this process will form some rich patches of bonanza ore, in some places valued at thousands of dollars to the ton.Alaska: Kodiak Islands Mineral Resources
March 2016
The fresh material is worked and concentrated by the waves on the flat, wide beach platform. The waves wash away the lighter minerals, leaving the heavies near the bluffs and in depressions on the beach.
The fresh material is worked and concentrated by the waves on the flat, wide beach platform. The waves wash away the lighter minerals, leaving the heavies near the bluffs and in depressions on the beach.
Gold in Quartz
February 2016
Because quartz and gold may be deposited together across a considerable range of temperatures, not all quartz veins are the same, and there are several different types of gold-quartz deposits.
Because quartz and gold may be deposited together across a considerable range of temperatures, not all quartz veins are the same, and there are several different types of gold-quartz deposits.
Northwestern Alaska Mineral Resources
February 2016
Gold and jade are actually only minor mineral resources for the Northwestern Alaska region as a whole. Modern prospecting has focused more on base metal than precious metal resources.
Gold and jade are actually only minor mineral resources for the Northwestern Alaska region as a whole. Modern prospecting has focused more on base metal than precious metal resources.
Electrum: Gold and Silver Together
January 2016
...if you are out prospecting and find something that looks very much like a nugget but has an odd greenish-gray cast to it, don’t be too quick to simply toss it aside as junk.
...if you are out prospecting and find something that looks very much like a nugget but has an odd greenish-gray cast to it, don’t be too quick to simply toss it aside as junk.
Mineralized Faults and Contacts in the Search for Gold
January 2016
Fault zones and rock contacts are important because the vast majority of gold and silver deposits, as well as those of many other metals, are formed by hot, mineralized water solutions.
Fault zones and rock contacts are important because the vast majority of gold and silver deposits, as well as those of many other metals, are formed by hot, mineralized water solutions.The Significance of Nuggets in Placers
January 2016
Chances are better that both types of gold did not come from the same source. Let's look at the probable conditions to cause two types of gold in a placer.
Chances are better that both types of gold did not come from the same source. Let's look at the probable conditions to cause two types of gold in a placer.
The Strange History of the Utica Mine
January 2016
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.
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.
Researching Mineralized Areas
December 2015
There are a load of ways to do research, and I’m going to talk about how I do it—maybe you’ll get some ideas that will work for you, too.
There are a load of ways to do research, and I’m going to talk about how I do it—maybe you’ll get some ideas that will work for you, too.
All About Minerals
November 2015
There are several common ways that new mineral crystals form and grow. Perhaps the simplest is when minerals form through the cooling of molten rock and the atoms bond together into mineral crystals.
There are several common ways that new mineral crystals form and grow. Perhaps the simplest is when minerals form through the cooling of molten rock and the atoms bond together into mineral crystals.
