History & Geology
Critical Metals: Copper
May 2012 by Chris Ralph
From time to time I’ve been doing a series on critical metals and how important they are to our complex and technological society. This month we are going to take a look at copper, and how important that metal is to our modern lives.
Eastern Arizona: Gold and Base Metal Deposits—Part I
Arizona is well-known for its copper-gold porphyries and massive base metal-gold sulfide deposits such that primary gold deposits in the state are often overshadowed.
Sulfides and Intergrain Gold Wire Nuggets
...these nuggets have not traveled far from the lode because the golden wire lattices would have been torn apart or flattened during weathering of rock and deposition by violent stream action.
The Goldfield Mining District -- Then and Now
In 1983, some of the ore yielded more than 2,500 ounces of gold within 30 feet of the surface. The shoot pinched to a narrow vein.
Kennecott Copper Mine, Kennecott, Alaska
For approximately 30 years, the mines produced good ore, some so rich it was simply sent straight to bagging, bypassing milling and loaded directly on the rail cars.
The Pearce Mineralized Area, Dragoon Mountains, Arizona
...I would bet considerably more lode gold and silver remains to be found in this area, and there are possibilities for small placers and nugget shooting.
Prospecting for Pegmatites
…in some cases pegmatites have produced individual mineral crystals that are enormous, attaining lengths of over 40 feet long, and many of the world’s largest mineral crystals are examples that were found within pegmatite deposits.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.
Subscription Required:
The Bawl Mill
• Ask the Experts: gold per ton; improving assay method
• Bering Sea Gold—Part II
• Tucson Show Marketing
• Ganes Creek Hits 10 Years—Part I
• Fabulous Florence—The Golden Town of Idaho
• Arizona's Vulture Gold Mine and Lost Dutchman
• Replacing Your 12-Volt Pump
• Melman on Gold & Silver
• Mining Stock Quotes and Mineral & Metal Prices
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Legislative and Regulatory Update
• Ask the Experts: Ionizing mercury
• El Tigre—Unlocking Values in Tailings to Jumpstart a Mine
