The Geology and Minerals of North Georgia

Geology of Yonah Mountain, North Georgia

There’s gold (and quartz) in them thar hills!!!

From our recent new homebase in North Georgia, let’s talk about the Blue Ridge and the Piedmont lands and the geology and minerals of North Georgia. We’ll look at them together, seeing as how the rocks there, the ones that got squeezed and heated up (that’s metamorphic, you know) and the ones that bubbled up from the earth like old volcanoes (igneous), well, they’re cut from pretty much the same cloth.

Now, the old-timers figure that way back yonder, the whole shebang of North America bumped right into this big ol’ landmass called Gondwana, and that’s how they got Pangea, this super-duper continent. That mighty clashing of the earth’s plates, it caused all sorts of cracks and wrinkles in the Blue Ridge and Piedmont here in Georgia. And all that pressure and heat? Why, it just folded and lifted those rocks right up.

The Blue Ridge Mountains, bless their hearts, they’re some of the ancientest hills you ever did see, a whole lot older than those young whippersnappers out west, the Rockies, and even them big fellas over in Asia, the Himalayas. When the Blue Ridge first poked their heads up, they’d have been some of the tallest things around, I reckon. But then the rains came, and the floods, and they just washed away tons and tons of rock and dirt down into the lowlands, the plateau, and even further out. Some folks who study rocks have even found bits of that old wash way out in Arizona, in the Grand Canyon!

Later on, that Pangea thing, which included these very Appalachian Mountains, well, it got all torn apart by more of that earth movin’ and shakin’. Scientists have found pieces of these same Appalachians way down in South America, over in northwest Africa, and even in Greenland, Great Britain, and Europe. But nowadays, all that’s left standin’ here are the tough old cores of these Appalachian rocks.

Now, up in northeast Georgia, them Blue Ridge Mountains make up the highest ground in the whole state. Here in Georgia, these rounded ridges and worn-down peaks go from about sixteen hundred feet up to nearly forty-seven hundred feet above sea level. The whole Appalachian chain goes even further, roughly from Alabama all the way up to New York.

The Blue Ridge, they’re known for that pretty blue haze that hangs over ’em, and for their mighty steep gorges, canyons, and waterfalls. Take Tallulah Gorge, for instance, down there in northeast Georgia. It’s a good six hundred feet deep, making it the fourth deepest canyon east of them Rocky Mountains. Mighty impressive!

Now, the southern edge of the Blue Ridge is near this thing called the Brevard Fault Line. Right on the other side of that line, you got the Piedmont, and it’s made up of some mighty old rocks too. The story goes that these rocks started out as just plain old muddy clay that settled way down deep in the ocean. Seems like mud gets carried the furthest from land that’s wearin’ away, mixes in with some sand, and then just sinks to the bottom of the deep blue sea. Then, when that mud gets squeezed and heated up (that metamorphism again), it turns into mica. And as most folks around here know, Georgia’s got plenty of that sparkly mica.

The rockhounds have also found a lot of this stuff called Metagraywacke, which is just sandstone that’s been changed by heat and pressure. Graywacke, that’s what they call the stuff before it changes, forms in layers of clay and sand that got sorted out in deep water with strong currents. The bigger bits of gravel and sand sink to the bottom first, and then the finer stuff settles on top. Over time, all that gets cooked and squeezed, and out pops Metagraywacke.

Now, there’s all sorts of different metamorphic rocks and minerals in the Blue Ridge area. That’s ’cause it’s been through a whole bunch of episodes with different amounts of heat and pressure and foldin’. Along the western edge of the Blue Ridge, where things weren’t quite as intense, you find slate and phyllite (some folks call it fillite). Then, as you go further in, you find minerals like chlorite (that forms at around two hundred degrees Fahrenheit), shiny silver muscovite, black biotite, garnets, and staurolite. And over on the eastern side, where things got real hot and squeezed tight, you can find kyanite (that takes about eleven hundred degrees Fahrenheit to form!), sillimanite, andalusite, some pretty zebra-striped gneiss, and even migmatites.

And that ain’t all! We got copper, marble (that used to be limestone, like around Tate), talc, this old blue quartz meta-granite (got its color from titanium), quartzite rings around Tallulah Dome, and even some of that igneous granite in the Blue Ridge. Why, even Mount Yonah over in White County is made of this granitic gneiss. It formed way back when molten granite pushed its way up into layers of metamorphic rock.

Now, one more thing you’ll find in both the metamorphic and igneous rocks of the Blue Ridge and the Piedmont is quartz. It can form when hot, watery stuff full of silica pushes into cracks in the rock and makes veins. And gold? Well, gold can be found in those same kind of veins, along with quartz and some other minerals like pyrite. In fact, if you see quartz veins that are stained with iron, that can be a sign that there might be gold nearby. Them gold deposits in the Blue Ridge led to the first big gold rush in America, right around Dahlonega, Georgia. Read our review of the Dahlonega Gold Museum here: http://www.americangeode.com/blog/dahlonega-gold-rush-museum-review/. You can also find a little bit of gold scattered in those igneous granites, but most of the gold folks have dug up over the years came from what they call placer deposits – that’s just old river and stream gravel that’s been worn away over time.

Remember to #getoutandrockhound and share www.americangeode.com with your rockhound friends!

Rockhounding, Hiking, and Exploring the Geology of North Georgia

Yonah Mountain

Since moving back to North Georgia in late 2024, American Geode are loving and appreciating the chances for rockhounding, hiking, and exploring all the geology and geologic wonders of North Georgia. The North Georgia geology is a lot of metamorphic, so while there are few fossils to be found, North Georgia is full of quartz, some garnets, some amethyst and the rare gold discovery in Dahlonega that kicked off the first American Gold Rush and the infamous “Trail of Tears” for the Cherokee Indians (http://www.americangeode.com/blog/dahlonega-gold-rush-museum-review/). One of the benefits and advantage of living in North Georgia are that we are in the middle of dozens of state and federal parks, with plenty of variety for hiking experiences in the mountains.

We recently visited the Charles Smithgall Woods, https://gastateparks.org/SmithgallWoods, for a day hike to see Mount Yonah. The Smithgall Woods were gifted to the state of Georgia by philanthropist Charles Smithgall who also started a dog and cat shelter that American Geode supports, https://charlessmithgallhumanesociety.org/. This hike is just under 2 miles and can be completed in less than an hour unless you stop to smell the Georgia mountain laurel and take selfies in front of one of the best views of Mount Yonah. American Geode hiked the trail called Laurel Ridge Trail, and it was a delight.

The American Geode team hiked it during the week, so the crowds were a little lighter than on the weekends. While rockhounding is technically not permissible, we enjoyed so much admiring the geology of the hike as it descends up and then down a mountain. We took so many pictures and spotted numerous varieties of butterflies and saw a copperhead snake from the distance, whom we did not approach but seeing a copperhead was magnificent and a thrill. Hiking is a great workout, and we look forward to hiking all the trails of Charles Smithgall Woods. See our pictures of Mount Yonah (aka Yonah Mountain around North Georgia) and imagine what a gorgeous landscape you will see depending on the day, weather, and time of year.

Contact American Geode directly for any advice or questions, and enjoy rockhounding North Georgia!

Yonah Mountain
Yonah Mountain
Yonah Mountain
Yonah Mountain
Yonah Mountain
Yonah Mountain
Geology of Yonah Mountain, North Georgia
Geology of Yonah Mountain, North Georgia

Paleoart collection of Original Vintage Artwork used for the American Museum of Natural History 2002 Calendar

Paleoart Original Artwork used for the American Museum of Natural History 2002 Calendar

American Geode are also paleoart, art, and antiques appraisers, dealers and collectors, and we very recently acquired the entire vintage private artwork collection of PaleoArt that was used in the 2002 calendar of the American Museum of Natural History, New York. The artist who had lived in New York City and worked at the museum, moved to North Georgia, which is also the homebase of American Geode now, and we have had the chance to become friends with her and share our love and appreciation for the museums of New York City, especially the American Museum of Natural History. Here is an article and review about AMNH from our most recent visit: http://www.americangeode.com/blog/tips-for-visiting-the-american-museum-of-natural-history-amnh-in-new-york/

These sketches are preserved under wax paper with the annotations and notes on the wax paper. The paleoart sketches themselves are so charming, educational, and cool; they speak for themselves. We are cataloguing this collection of PaleoArt and will offer it for sale sometime this year.

Please contact American Geode directly if you would like more information. We will also be posting images on social media, https://x.com/AmericanGeode. Below is just a portion of this magnificent special PaleoArt collection.

PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
Paleoart Original Artwork used for the American Museum of Natural History 2002 Calendar
Paleoart Original Artwork used for the American Museum of Natural History 2002 Calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar
PaleoArt for the American Museum of Natural History 2002 calendar

Knoxville Gem & Mineral Society 2021 Show!

Knoxville Gem & Mineral Society 2021 Annual Gem Show

Rothchild Conference Center 8807 Kingston Pike, Knoxville, TN 37923

Friday, October 15, 10:00 am – 6:00 pm Saturday, October 16, 10:00 am – 6:00 pm Sunday, October 17, 11:00 am – 5:00 pm

As a precaution for Covid masks will be required for admittance.

The show will feature 23 vendors with a wide variety of jewelry, fossil and mineral specimens, meteorites, gemstones, and decorative objects. There will also be educational activities and gem and mineral ID tables. Admission Adults: $6.00 Run of Show Pass: $10.00 Children Under 12: Free

Summerville, Georgia Agate Rockhounding Trip 2021

Summerville Georgia lace agate

Through one of the gem and mineral clubs to which we belong, we were invited to rockhound for lace agate, banded agate, moss agate, and druzy quartz from a private mining site near Summerville, Georgia.

I arrived and was lucky to have the entire mining area to myself except, over the course of the morning and afternoon, 2 different couples stopped by to collect agate, and a family was out on a rockhounding trip.

American Geode takes that attitude that if you can, take a lifetime supply. We filled up every bucket and bin we brought, and also picked up many large and heavy agates. The stone was plentiful. The only time we used our tools was to break apart a behemoth stone into more manageable sections. We found moss agate, lace agate, banded agate, and our favorites had druzy quartz pockets.

The beauty of these stones were not easy to see without being splashed with a little water, but we ran out of water, so started collecting more than enough to overcompensate as we expected to have some stones better suited for the garden. On a recent gem and mineral meeting over Zoom, when I was showing off these fine agate specimens, I learned that the agate, and the stone formation containing covers a lot of Northwest Georgia, even into Tennessee, but it is on private land, or federal park land, so not available or accessible to the general public.

This agate tumbles well, but it loses a lot of surface area during the tumbling. It is beautiful however, and we are sure that a cabochon or lapidary person would have even more fun with this agate.

We are selling this agate here: https://www.ebay.com/usr/americangeode