History & Geology
PGMs in the United States
August 1999 by Edgar B. Heylmun, PhD
Until just recently, platinum-group metals (PGMs), especially palladium, had been holding their own on the market. But, Russia has now resumed shipments and it has brought prices down.
Enrichment of Mineral Deposits by Weathering—Part I
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.Calcite and Limestone
The other distinguishing feature of calcite has to do with its chemistry. Geologists sometimes take a small bottle of dilute hydrochloric acid out into the field with them because calcite reacts with acids to make a bubbly foam.
Gold, Quartz & Chalcedony—Part II
The specific gravity of chalcedony is 2.58 to 2.64. This is slightly lower than coarsely crystalline quartz because of slight porosity in chalcedony. Being so light, it will easily wash out of a gold pan.
Ask The Experts
Sulfides and oxides—what's the difference between the two?
The Geology of Diamond Deposits
New theories have been developed and they may lead to new discoveries and give prospectors some new insight on where to look for diamonds.
The Wild Rush to Find More Cobalt—Part I
While some future cobalt will come from recycling lithium batteries and other products, the coming huge need for cobalt is virtually a perfect storm of heavy demand and insufficient supply.
The Silver Islet Mountains of Utah
I set up my dry washer on the north side of the cut and sampled the bed rock and dumps around me. As I was only sampling, I ran for 20-30 minutes, shoveling from a variety of areas.
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