History & Geology
Critical Minerals: Tungsten
July 2017 by Chris Ralph
Because tungsten minerals are heavy, exploration can be done using stream sediment samples. Prospectors looking for gold have found scheelite or wolframite in their placer concentrates, and in some cases this has led them to make important tungsten finds.
Gangue Minerals - What Do They Tell Us?
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.
Ancient River Channels of Trinity County
Trinity County is located in the far northwest corner of California and stirs up many different memories for those who have been there.
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.
How to Recognize Hard Rock Gold Ores
I regularly get inquiries along the line of: “Hey, I found this rock, and I think it might be gold ore. How can I tell?” Prospectors are always on the lookout for gold-bearing rocks that may be the source of any nearby placer gold.
Sierra County Gold—Part I
...this county contained some of the richest placer ground found in all of California and still produces some pretty impressive finds to this day.
Large Gold Deposit Types
It is not necessary to have a PhD in geology, but you need to know the basics, so that’s what I am going to try to dig into here—the understandable basics of these gigantic gold deposits.
The Amazing Mineral Tourmaline
It is a gemstone, and yet it is also closely associated with many types of metal ores. It's valuable itself but often points toward other valuable minerals—that is certainly something prospectors want to know more about!
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