It was late morning, and my son, Steve, and I were driving the backroads of Western Illinois. We were out to finally fulfill a long-time quest: that of finding a geode in the wild. What is a geode you ask? You’ve probably seen them for sale in souvenir shops but just in case you don’t know the details:
Simply stated: geodes are hollow rocks lined with crystals or other minerals. However, their origins go back hundreds of millions of years ago in which bubbles formed in lava or earth and over time rainwater has seeped minerals into them. These minerals crystalize and over millions of years crystals are gradually built up in the inside space. To me, the process is very similar to how beautiful formations are built within caves, but on a much smaller scale. Geodes are found all over the world but one of the largest concentrations of them is found around Keokuk, Iowa in something called the lower Warsaw Formation, a widespread rock unit of Mississippian age. That’s where Steve and I were headed. (Note: neither of us is a geologist, we’re just two guys looking for cool rocks!)
After about two hours drive we pulled into our target location: Jacob’s Geode Mine just outside of Hamilton, Illinois. We went the office where we told the owner that we had no geode experience and we wanted all the information we could get. He pointed to a hand-drawn map on the door which showed the location of his two geode mines. Mine #1 produces the largest geodes and you have to dig “below the brown dirt” to find them. Mine #2 produces the best quality geodes but “you have to chisel them out of the shale.” He said that each 5 gallon bucket we haul out costs $20 and he pointed out some tools on the ground that we could borrow. The entire briefing took less than 3 minutes. On the way to our truck I asked the owner if he thought we’d actually find a geode. He just laughed and said the last guy found ten gallons worth. Steve and I were still skeptical.
We decided to try Mine #1 first as we wanted to find some big geodes. We were able to pull up to the side of the mine and could see where the dirt had been gouged out by a bulldozer. We grabbed our tools: shovel, pickaxe, rock chisel and hammers and made our way into the mine. In moments we had found our first geodes…golf-ball sized round rocks just scattered around. It was like someone had just thrown some little ones back! We grabbed a hammer and broke a few open just to be sure. Yep, these were geodes!
Now, we wanted to find some bigger ones so the harder work began. With shovel, pickaxe and rock hammer we dug into the hardened soil about 4 to 6 feet below the surface and below the brown dirt. In short order Steve unearthed a grapefruit-sized geode, and then another and then another! It was like a cluster of grapefruits! In about 90 minutes of digging we had unearthed almost ten gallons of geodes!
Now, we wanted to find the higher-quality geodes so we set off deeper into the woods to Mine #2. There we drove into the mine which was about a twenty foot gash into the hillside. We grabbed our tools and climbed up to where we could see evidence of geode mining. Here we were faced with shale, hard sheets of horizontal rock with occasional round bubbles in them. This was hard work chiseling out stone inch by inch until you could finally pull the geode out of the rock. This was so cool, but so exhausting. We were at Mine #2 for another 90 minutes, topping off our two 5 gallon buckets with more geodes.
It was a long ride home filled with anticipation for what might be inside our treasures. We took all the rocks into Steve’s apartment and laid a tarp on the floor. Then we used a rented soil-pipe cutter to try to crack open some geodes. There we found out just how hard geode shells are as it took the force of two men using the leverage and cutters of our tool to crack the bigger geodes. One of us would be pulling down on the cutter’s bar as the other stood on the geode to hold it down. Finally, you’d hear a “pop” and then we would eagerly open it to see what treasure was inside. Primarily, our geodes had clear and orange quartz with some iron oxide. Some of them also had flecks of pyrite and other sparkly material. Too cool!
We divided up the remaining geodes with each of us ending up with about 5 gallons of rocks. I brought mine home and the next day had a geode-cracking party with 5 grandkids and my sister Sheryl. It took about 2 hours and all the energy of the seven of us to crack open all those geodes but it was worth it! Every rock yielded a different discovery and every rock was a treasure!
Geode hunting is great if you love the outdoors and if you love to discover new treasures. It’s fun for all ages but you will need to help everyone be safe because of all the tools and the difficult footing. Some of the mines, like Jacobs offer free tools to borrow but you’ll need to call ahead to be sure. I highly recommend renting a soil pipe cutter: ours was $35 a day. Below are some links to help you get started: