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NC Geology facts and factoids: Gold and hiddenite

January 3, 2013

Every now and then I get tired of answering the same questions over and over again, so I write something to treat that question in detail. Then when I get the question, I direct the questioners to the article, roll over and go back to sleep.

The first article addressed the question of  The First Gold Rush in North America: North Carolina or Georgia?  Looking into the question in detail yields some interesting results.

Schoolkids in North Carolina are taught the story of Conrad Reed, skipping church to shoot fish in the creek, and finding a huge gold nugget instead. That was in 1799.  Gold was first discovered in Guilford County, North Carolina, and sent to Governor Josiah Martin in 1774. Gold was later found in Virginia in 1787, as recorded by Thomas Jefferson himself. The reality is that “gold fever” spread exactly like a disease, starting at the Reed property in 1799 (now Reed Gold Mine State Historic Site, well worth the visit), then to the neighboring farms, then to that region of North Carolina. These weren’t really gold rushes, they were just the development of a new money-maker in the communities. In 1828, the Brindletown Gold Rush started in Burke County, North Carolina. Winter of 1829-1830 saw the spread of the fever throughout the Southeast with the start of the Dahlonega Gold Rush in Georgia.  In 1849 gold was discovered in California and the gold fever was a nationwide phenom. Historically, it grew exponentially like any other disease, with isolated cases in 1774, 1787, and 1799.

The second article dealt with the question “Is the mineral hiddenite found only in North Carolina?”  On a regular basis, somebody in a gem and mineral club will get into an argument with someone else about that question.  I would get the call to arbitrate the disagreement.

I set the second question against the backdrop of mineral nomenclature and 19th Century amateur mineralogists behaving like children.  Mineral nomenclature can be a real snooze, but in this case, it’s important because there is no internationally and  scientifically recognized mineral species named hiddenite.  There are formal and detailed means of naming minerals, intimately tied to the science of mineralogy, all under the oversight of the International Mineralogical Association (IMA). By these standards, the formal name should be “chromium-bearing spodumene,” the chromium being the source of the anomalous green color.  Hiddenite is a historical leftover,  a gemstone name, and there really isn’t anyone in charge of names of gemstones. In reality, every few years a new gemstone name will crop up as part of some marketing campaign.  Mineral names are science, gemstone names are marketing.

Back to the question about hiddenite.  Some people insist that only a gem-quality spodumene that is green due to chromium can be called a hiddenite, so hiddenite is only found in North Carolina. This isn’t true. A search of the scientific literature revealed sites from Siberia, India and Brazil. There are actually more reported sites, but I only list the ones where they published their chromium data.  One thing I didn’t go into in the article is that all of these discoveries come from pegmatite districts that also have emerald. An emerald is (often) a pegmatite mineral, a beryl that is green because it contains chromium.  If beryllium pegmatites interact with a chromium-bearing wallrock to make emerald, then spodumene pegmatites can do the same to make hiddenite. Not only is hiddenite not limited to North Carolina, it’s reasonable to expect to find it in pegmatite districts that contain emerald.

Future geoblogs will deal questions such as

  • Are the Appalachians (the Brushies, the Uwharries, etc.) the oldest mountains in the world?
  • Is the New River the oldest (second oldest, etc.) in the world?
  • Does North Carolina contain more minerals (more different minerals, more gemstones, etc.) than any other place in the world?

All of these are what I call “fake superlatives.” It’s the sort of thing seized upon to attract interest, without a lot in the way of fact checking. I’m really not interested in debunking these claims.  The fun part is that each answer is more complex than expected, and illuminates a new facet of North Carolina geology, and illustrates the way that geologists work and think.

8 Comments leave one →
  1. January 3, 2013 4:14 pm

    Reblogged this on NC Museum of Natural Sciences Blogs and commented:

    by Chris Tacker

  2. January 3, 2013 10:41 pm

    Updated with a link to the Reed Gold Mine State Historic Site.

  3. February 20, 2013 8:39 am

    So why are the lovely crystals on display in the NRC labeled Hiddenite instead of chromium-bearing spodumene?
    Removing the Hiddenite label now would raise a ruckus, but adding information about spodumene would be helpful. (If it’s there, I’ve missed it or forgotten.)

  4. February 20, 2013 10:51 am

    Beats me. I wasn’t involved in any part of that donation or the exhibit design.

  5. February 27, 2013 2:44 pm

    Hi Todd,
    We use “hiddenite” on the exhibit labels for the same reason we use “emerald” instead of “chromium-bearing beryl.” (“Emerald” does not appear as an official mineral name in the IMA database either. “Beryl” does.)

    While “hiddenite” is not the official mineral name, as Chris notes, it is an accepted common name for the gemstone. We use common names to describe animals as well, even though there is often dispute over them, with multiple common names given to a single species. There is less dispute (though still some) over the Latin names that scientists use, and if we wanted to be the most accurate, we would ONLY use the scientific names of plants, animals, and minerals on exhibit labels.

    However, we feel that the common names are more accessible, and readable, for our audience. With “hiddenite,” we hoped that local visitors would recognize the name of the town Hiddenite and make the association with a locally-found gem. If we used the more technical name, that association would be lost on most visitors. And while I agree that adding information about spodumene to the label would be educational, it would also have other ramifications for exhibit labels, in terms of word count and consistency.

    I hope that clears things up a little!
    Wendy, Exhibit Developer

  6. Billy Starnes permalink
    October 14, 2013 8:38 am

    I live in Stony Point and Im interested in learning more about the minerals found in the tin spodumene belt ..

    • christacker permalink
      October 14, 2013 11:08 am

      Hello, Mr. Starnes, you can probably find papers at the USGS site (currently shut down) that deal with historical exploration in the tin-spodumene belt. That would be the region around Bessemer City and Kings Mountain. I know that one of the older tin mines was unearthed during excavation for a new highway, but I’d have to look in my noted to find the details. The best guide to historical mining in North Carolina is North Carolina: Its Geology and Mineral Resources, by Jasper Stuckey (1965) starting on page 332.

      • Billy Starnes permalink
        October 14, 2013 11:28 am

        Thanks for the input.Ive read that the tin spodumene belt runs through Hiddenite south towards Lincolnton.

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