All Articles
Mineralized Calderas in Colorado
May 2002 by Edgar B. Heylmun, PhD
A caldera is a large circular volcanic depression caused by collapse due to the removal of molten magma from an underlying magma chamber. The removal of magma is due to explosive venting of lava and pyroclastic material.
Additional articles that might interest you...
North Korea Seeks Outside Help to Modernize Mining
March 2002
Eager to earn hard currency, isolated North Korea is trying to modernize its decrepit mining industry with foreign help.
Eager to earn hard currency, isolated North Korea is trying to modernize its decrepit mining industry with foreign help.
Gemstones
October 1999
by Ronald F. Balazik
Excerpted from USGS Mineral Industry Survey's 1998 Annual Review
by Ronald F. BalazikExcerpted from USGS Mineral Industry Survey's 1998 Annual Review
The Bawl Mill
March 2006
• Why rent when you can own?
• County taxed by tax error
• Military policy wins out over common sense
• Why rent when you can own?
• County taxed by tax error
• Military policy wins out over common sense
Mining Stock Quotes and Mineral & Metal Prices
December 1999
Where To Find Diamonds
November 2008
Where to find diamonds in the United States: It is somewhat common for gold prospectors to find diamonds in black sand concentrates and not recognize them.
Where to find diamonds in the United States: It is somewhat common for gold prospectors to find diamonds in black sand concentrates and not recognize them.
Our Readers Say
December 2001
This is in response to Norbert Beckstrom’s letter in the November issue of the ICMJ. He wrote in reference to a letter by Jerry Hobbs in the October issue. If anyone opened up a can of worms, it is Mr. Beckstrom.
This is in response to Norbert Beckstrom’s letter in the November issue of the ICMJ. He wrote in reference to a letter by Jerry Hobbs in the October issue. If anyone opened up a can of worms, it is Mr. Beckstrom.
The Bawl Mill
January 2000
• Australians know how to do a fundraiser
• She shared a toothbrush but...
• This IRS employee will share her winnings—with the IRS!...
• A diamond is forever (almost)...
• Australians know how to do a fundraiser
• She shared a toothbrush but...
• This IRS employee will share her winnings—with the IRS!...
• A diamond is forever (almost)...
Subscription Required:
The Bawl Mill
• Our Readers Say
• California Wilderness Coalition and The Nature Conservancy Recruit Government Employees to Carry Out Huge Land Grab
• Drywashing Rules Clarified
• The Keystone Gold-Copper District, Medicine Bow Mountains, Southeastern Wyoming
• Picks & Pans: Mining Tungsten Ore—A Case History
• Gold in Oregon
• Aussie Gold—A Look at the Northern Territory
• The Phoenix Gold Mine: A Brief History
• Calico Mine
• Mining Stock Quotes and Mineral & Metal Prices
• Looking Back
• Melman on Gold & Silver
