Kansas is a state with wonderful mineral diversity, ranging from opal to septarian nodules. There are a lot of places for the intrepid rockhound to take a look and see what they can find. It’s just a matter of getting out there, and making sure that you’re in the right area!
So, let’s take look at our list of some of the rocks, minerals, and gemstones found in Kansas to see if you’re ready for a new expedition.
Minerals and Gemstones Found In Kansas
These three forms of cryptocrystalline silica are a source of contention, so I usually lump them together. They’re all comprised of an intergrowth of quartz and moganite, both crystallized forms of silica. These bind together and create a crystalline structure that requires a microscope to explore, but the end effect is a glassy or waxy stone with beautiful coloration.
Kansas is particularly rich in agate, with some jaspers scattered around. Indeed, you can even find Lake Michigan agates in some locations. These were deposited aeons ago by glaciers as they moved south, leaving behind agates that are far removed from their original home.
Agate and jasper are almost always found in the gravel of riverbeds and creek beds in the state of Kansas. You should be able to find something in most waterways, but some are particularly rich. In addition to the Lake Michigan agates, you can also find awesome moss agate in the southern portions of the state.
Some of the better locations are in the following places:
- Blue River
- Smoky Hill River
- South Fork Solomon River
The first two are known for Lake Michigan Agate, while the latter is known for its own variety of moss agate.
Don’t get too excited, the opal that comes out of Kansas isn’t the precious kind most of us associate with the word. Instead, it’s what’s commonly known as “potch” or common opal. Like chalcedony, opal is a silica-based mineral but its formation lends it drastically different properties. Even if it’s not quite the gem you were thinking of.
Opal is comprised of a dense formation of amorphous silica with some water. The silica is arranged in microscopic spheres, creating a stone that entirely lacks crystal formation but isn’t quite a glass. Actual silica glass with a natural origin is generally obsidian.
Common opal is still an awesome mineral. It carves very well, can be cut into cabochons, or just enjoyed as is once the dirt has been removed. Coloration varies but in Kansas, it’s mostly white. That doesn’t mean it lacks interest, Kansas is also a major source of dendritic opal. Dendritic opal has small, tree-like inclusions formed of manganese oxide.
Opal can be found in the following locations:
- Rawlins County
- Ness County
- Wallace County
It will generally be found in limestone formations in those regions.
Geodes are hollow, round-ish rocks that hide crystals of some other mineral. They’re often quartz or calcite, with the ingrowth of the crystals readily apparent once the stone has been cut. Quartz geodes often have a layer of chalcedony around the exterior. Some stones are completely filled with chalcedony, these are usually known as “thunder eggs.”
The geodes of Kansas are usually calcite or quartz, but there is also chalcedony in some locations. They’re not quite as famous as the Keokuk Geodes found in Iowa but they can hold their own against most places.
Geodes are usually easy to recognize. They’ll be potato-shaped or round, often just a few inches across. They’ll usually feel lighter than a stone their size should feel, but that’s not always the case. They can also be heavily filled with material or the sheer density of the crystals can make up for the lost volume of the host stone.
If you’re looking for geodes, waterways in the following areas are known to host them:
- Butler County
- Marshal County
- Near Milford Lake
It’s worth a shot to see what you can find, Kansas hosts geodes with chalcedony, quartz, and calcite.
4. Petrified Wood
Petrified wood is, strictly speaking, a form of silica. The vast majority of them are ancient pieces of wood that were replaced by chalcedony over the millions of years they were underground. Some of them are opalized, and many locations host varieties that are hard to even recognize as wood due to the intense coloration.
Kansas has quite a bit of it, but it tends to be of the normal brown color. While not colorful it does tend to be a wonderfully dense material and many pieces will ring like glass when struck. My personal favorite limb cast came from Kansas actually, you could be forgiven for mistaking it for a random chunk of wood sitting on a shelf due to its color and form.
These woods can be found in most waterways. Petrified wood is a surprisingly common stone and it often erodes from its initial location before being carried along to end up far from home. It can also be transported by glacial action. While it often moves down from larger areas with a lot of petrified wood, this may not always be the case. On occasion there can be much smaller pieces of wood that simply got trapped in the right way.
If you’re looking to find a wooden fossil, then the following spots offer a good chance:
- Aetna, Barber County
- McClouth, Jefferson County
- Jackson County
The above are only some samples of the many areas. Petrified wood tends to be spread out in this state, rather than concentrated in forests, so you’ll have to experiment with locations to find the best spot.
Quartz is a macrocrystalline form of silica, meaning that we can see the crystalline structure with the unaided eye. It’s also the most iconic of crystals, the hexagonal form and sharp termination can be seen in most art depicting them. It’s so well known for its properties that we just call large pieces of quartz “rock crystal” and leave it at that.
Quartz forms in points, clusters, and geodes depending on the locality. Points and clusters are often found in pegmatites, which are extremely coarse-grained stones that have large crystals in parts of their structure. Geodes can be found in many places, from waterways to ancient volcanic ash beds. They’re an ancient form of concretion and quite common in certain regions of Kansas.
In Kansas, you’ll be looking for geodes. I was unable to find a place that has the other forms in the state but there are plenty of beautiful quartz geodes available. The most well-known location is Flint Hills which has a wide variety of different geodes. You can also go to any other location where geodes are known in the state, most of them will have a quartz interior.
Dolomite is a weird name since it covers both a stone and a mineral. The stone is so-named because it contains a ton of the mineral dolomite but it lacks the beautiful form that makes most hunters seek it. The mineral is calcium magnesium carbonate which produces impressive crystals. While usually tinged with color, pure dolomite actually forms into clear crystals.
Dolomite stone is common, but good crystals of dolomite are harder to find. In Kansas, there are some particularly impressive samples available. These are usually light pink in color with a form similar to dog tooth spar calcite. They’re primarily concentrated in the Southeastern portion of the state, in the Tri-State area.
Dolomite is more important than it seems. It’s used in many processes, such as balancing pH in saltwater aquariums or garden soil. More importantly, dolomite is soluble in even slightly acidic water. Large formations of dolomite often point to a lot of underground water in aquifers, so its presence is important for far more than a couple of crystals.
If you’re seeking dolomite in Kansas then you have a few choices:
- Near Point of Rocks
- Near Hutchison
- West of Baxter Springs
The latter location is covered in areas that are rich in dolomite and offers your best chance. Just don’t run afoul of any of the various commercial mines which dot the landscape there.
Anhydrate, or calcium sulfate, is a common feature of salt formations. It’s relatively rare, water-soluble, and quite soft for a stone. In essence, anhydrite is actually a form of gypsum, just one that lacks moisture entirely. Upon exposure to moisture, anhydrite can become gypsum.
Anhydrite is closely associated with formations that have a lot of sodium chloride (table salt) or potassium chloride. These salts remove moisture from the area rapidly, and when the temperatures are also high then anhydrite formation can occur. Anhydrite has been produced in labs by mimicking the nature of its formation.
Most of the anhydrite found in Kansas is in the Southeastern corner, but it also occurs near salt mines in the central portion of the state. Anhydrite is rarely found on its own, you’ll usually find it while picking up other sulfide or sulfate minerals. In Kansas, these include Galena, Pyrite, and Chalcopyrite depending on the location.
This close association with ores makes anhydrite an important geological marker for prospectors, but most of us just want a nice crystal formation for the shelf.
8. Septarian Nodules
Septarian nodules are a strange form of concretion. They’re round nodules with an exterior that has white lines cutting through them. These often resemble a turtle’s shell and when polished they present a visually complicated array of minerals. Most of those sold online come from Madagascar, but they’re actually present in Kansas!
Septarian nodules are thought to form by the minerals inside of them shrinking down after cooling. The lines on the exterior are often calcite, which would easily form over the course of the millions of years it takes for a septarian nodule to form. These nodules can be cut open, polished, or left as-is depending on what you’d like to do with them.
Kansas’ septarians are great examples of the nodule’s formation in many cases. When cut open it’s easy to see how the calcite formed in the cracks of the cooling nodule, often spiderwebbing throughout the entire stone. Whole nodules are easy to recognize, but be aware that many pieces of septarian nodules are also scattered after being broken down through erosion and time.
The vast majority of these nodules are found in Osborne County, just south of Hobbie Lake. They’re also found in the waterways of the adjoining counties and a few other places scattered across the state.
Chalcopyrite is a copper iron sulfide mineral, similar to the classic iron pyrite with the addition of copper. It forms into beautiful masses of tetragonal crystals. These are often the same brassy yellow as pyrite until the atmospheric oxygen begins changing the exterior of the stone. It’s actually a commonly found item in rock shops.
Chalcopyrite oxidizes on the exterior, and with some care, this process can be controlled. The end creation is sometimes known as “Peacock Ore” due to the wide variety of colors. These treated stones often show some iridescence as well. Some peacock ore is actually bornite or a combination of the two. Most cases of heavily colored chalcopyrite are artificial.
Chalcopyrite is also a good ore of copper. Copper can be extracted from the material with just the addition of silica sand, making it one of the easier ways to access the orange metal. It’s closely associated with iron pyrite and other sulfide minerals, sometimes even forming in combination with pyrite to create truly unique mineral samples.
Chalcopyrite can be found in Kansas in the same place as other sulfides. That is to say Cherokee County in the Tri-State Area produces the majority of chalcopyrite found in Kansas. Hunting the hills in the area is your best chance to bring home a sample of your own.