Ask The Experts: What is a Spanish needle?
July 2017 by Chris Ralph
Some fellow in Texas was selling a Spanish needle—a dousing device used to recover minerals in the old days. Do you know anything about these?
Q: I believe I have found a deposit that contains iridium. What can you tell me about iridium? Are there any tests I can do in the field to confirm it is iridium? How much is iridium worth? Where can I get it assayed? Can I refine it myself?
Q: Is this gold or some other metal?
Q: The Arizona BLM state office has started sending out registered letters to association placer claim holders...
• Are these gold amounts large enough to interest a mining company?
Q: About 158,000 tons of ore is estimated to remain on the property. Worth further investigation?
While there is no metal detector that will see only gold, there is a device that can reliably distinguish gold from lead, copper, iron or other metals. It is an X-Ray fluorescence tester, sometimes called an XRF gun.
Market for scheelite concentrates?
The Bawl Mill • Ask The Experts: Sulfides and fluxes • Legislative and Regulatory Update • Simple Rules of Gold Geology: Comparing Epithermal and Mesothermal Deposits • The "Madonna Nugget"—A Weekend Hunt to Remember • The Goldfield Mining District, Nevada—Part II • Sunset Sunbaker • A Prospecting Adventure in Mexico • Critical Minerals: Tungsten • Police Urge Author to End Treasure Hunt • Melman on Gold & Silver • Mining Stock Quotes and Mineral & Metal Prices