GMS Field Trip October 2025 (2 of 3)

GMS Field Trip
Geodes and Mississippian Fossils in Kentucky
Sunday, October 5, 2025

Although the first field trip of October and this trip, the second field trip of October, were only a few miles apart, the specimens were millions of years apart. The first trip was Late Ordovician, and this trip was Mississippian, about 100 million years younger. Members found plenty of geodes, a few fossils, and, my favorite, some quirky beekite.

The geodes we find are sedimentary geodes, so they don’t have colorful banding around the rind that geodes from western states and Mexico often have. These geodes look better if you break them open instead of sawing them open; plus, many are solid, so members were encouraged to break them on the spot.

The Knoxville Gem and Mineral Society (KGMS) co-hosted the trip, and KGMS field trip chair Daniel Miller brought his geode cracker. He made the device with scavenged parts including a 12-ton bottle jack and a chain from a soil pipe cutter. Using the hydraulic leverage of the bottle jack, he slowly tightened the chain around each potential geode until it broke in half. He also placed a 1-gallon baggie around each one to catch tiny, loose quartz crystals, and to contain any fragments that might fly out.

Members were delighted when the geodes popped open to reveal quartz crystals inside. Once they are home, they will need only a warm bath with a bit of toothbrush scrubbing, and the geodes will too. All kidding aside, the geodes usually look pretty good just cracked, so minimal cleaning is necessary. Charles cautions people from over-cleaning geodes like these. A bit of staining actually helps with contrast versus rocks that are cleaned with acid until they are stark white.

The fossils in the area are usually small, and they tend not to have very fine details, but they are still fun to find. Corals and crinoid stems play hide-and-seek in the gravel, so you have to look slowly and closely. This time, I saw some horn corals, another type of coral, and a nice little crinoid stem. More about that one later.

My favorite thing to find there is beekite. It is a form of chalcedony that appears as concentric rings. Researchers say that the rings form as silica replaces calcite, often the calcite in shells, but it can also be calcite in rocks. The rings I see are either fine, thin rings that look sort of wrinkled, or they are thicker, and look like tiny concentric bagels. Either way, they have a weird, cool, alien appearance and are super fun to find. This time, one of my favorite beekite pieces is the crinoid stem I mentioned earlier. It’s the first time I have found beekite on a crinoid stem, so I was thrilled when I noticed it. Another member who had never seen beekite before, quickly turned up a large rock, possibly a geode, with beekite all over it, and even better, some of the rings are pink!

Another fun specimen joining my collection of the weird is a piece of chalcedony that looks like a mushroom or muffin. The top has a conchoidal area where some of the chalcedony chipped out. The area is smooth, so the break was not fresh. It created a window that provides a peek inside, revealing tiny flower-shaped structures. I am not sure if the “flowers” are an indication of coral or perhaps shapes formed by quartz crystals. Whatever they are, I am very fond of my mushroom muffin, and I am working with Charles to determine if there is a way to polish the window so the flowers are easier to see.

Many thanks to the property owner who graciously gives us plenty of parking space where cows might lick our cars, and allows us to tromp around on his gravel looking for geodes and other weird stuff! Everyone had a great time and went home with plenty of goodies. Thanks to Daniel for bringing his geode cracker and cracking all the rocks member brought to him. And thank you to members who picked up as much trash as they could (not as much as in prior years, so we have been doing a good job), and for showing me their favorite finds. And, of course, thank you to Charles for arranging the trip!

Lori Carter on behalf of Charles Carter
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