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Chert is one of the most frequent and popular sedimentary rocks in the world. It is constructed of microcrystalline quartz, which contributes to its high Mohs hardness, and comes in a variety of colors, most notably red, brown, gray, and green.
Chert is often confused with flint, which is a higher-grade material that was commonly used in the creation of tools such as arrowheads or knives. However, flint is a variety of chert. Some U.S. states where you can find common chert include Missouri, Pennsylvania, and Florida. It is often discovered interbedded with shale and limestone.
Let’s look at how chert is formed, where it can be found, and which states are best for discovering chert specimens!
If you want to check out the best rock and mineral identification books, you can find them here (Amazon link).
Where to Find Chert Rocks Near Me (Most Common Environments)
Chert may arise in a variety of ways, but the most prevalent is by biological causes. Diagenesis is a process in which marine plankton siliceous skeletons disintegrate and silica precipitates, forming chert rocks.
Areas with a rich history of volcanism also result in chert formations, while chert can also form near hot springs or banded iron formations. Chert is also often found interbedded with shale or limestone. Other typical environments to find chert include gravels, beaches, mines, quarries, road cuts, exposures, streams, and creek beds.
Let’s explore some of these mediums and see exactly why you can find chert there.
If you want to check out the best rock and mineral identification books, you can find them here (Amazon link).
Quarries and Mines
Since chert is a relatively common rock, quarries, pits, and mines are some of the best environments to find. Regions with a rich history of volcanism are more prone to have chert deposits than others.
Beaches, Creeks, Streams, Washes, and Draws
Tiny silica fossils significantly contributed to the formation of chert rocks, especially those at the bottom of the ocean. In such formations, shale is also commonly discovered.
Because of this, beaches are also among the best environments to find chert specimens. Gravels, creeks, streams, washes, and draws are potentially significant areas in which to discover various types of chert.
BTW: Do you want to know more about rock and mineral identification? The books listed below are the best ones you can find on the internet (Amazon links):
- Smithsonian Handbooks: Rocks & Minerals
- Gemstone & Crystal Properties (Quick Study Home)
- Ultimate Explorer Field Guide: Rocks and Minerals (National Geographic Kids)
Road Cuts, Exposures, and Outcrops
Road cuts, outcrops, or exposures are other fantastic mediums to discover chert rocks. If you ever find a limestone exposure, it’s almost guaranteed that you will also find chert specimens since they form there as nodules.
TIP: Sedimentary and igneous rocks are among the basic types of rocks. Check out the main differences between these rock types in the article below:
Sedimentary vs. Igneous Rocks: Differences & Similarities
Where Can I Find Chert Rocks in the USA? The Best Locations
As you can see, there are many environments where you can find chert specimens. If you want to go hunting for chert in the U.S., it’s essential to keep the environments mentioned in mind and that some states are more abundant in this type of sedimentary rock than others.
The best states in the U.S. to find chert include Florida, Missouri, Pennsylvania, Virginia, Wyoming, Kentucky, Oklahoma, Iowa, Tennessee, Utah, Nevada, Georgia, New Mexico, Washington, Ohio, Oregon, Michigan, and California, among others.
| State | Locations |
|---|---|
| Missouri | Bee Bluff, Greenfield, Hermitage |
| Florida | Alachua County, Marion County, Sumter County |
| California | Coyote Point, Morgan Hill, New Almaden |
Although no U.S. state has chert as its official state rock, some states have designated other varieties of chert as their official state rocks.
For example, Ohio has flint as its official state rock, while Missouri designated mozarkite as its official state rock, which is also a variety of chert. Let’s explore some of the states mentioned earlier and see exactly where you can find chert specimens!
Missouri
Missouri is probably the best state in the U.S. to find chert specimens due to its abundance here. Missouri’s official state rock is Mozarkite from 1967, a type of chert rock.
Let us begin by looking at the northeastern section of Missouri! Chert nodules in limestone deposits at Saint Charles Quarry. Southwestern Missouri is often the richest in chert specimens, particularly the mozarkite type.
Mozarkite chert may be found in quarries and gravel pits in Lincoln and Warsaw, as well as in the low hills west of the Ozark Uplift. Regular chert is readily found at Greenfield in almost all gravel regions and exposures.
Gemmy chert specimens regarding road cuts and creek banks are present at Hermitage. If you want beautiful gem-quality blue chert specimens, head to Elk River near Bee Bluff.
Another important place is the area around Timber Knob. Here, you can also find gem-quality chert specimens with yellow bands.
In Southeastern Missouri, enormous gem-quality chert nodules may be found in the Current River, near Doniphan, as well as gem-quality flint specimens at Doniphan, which lies to the east.
Regular chert examples may be found in all of the gravels and streams south of Dexter and in mining wastes near Old Mines. If you visit Missouri, try your luck at finding mozarkite chert, which is rare and would make a lovely addition to any Rockhounds collection.
TIP: Check out this article for a complete rockhounding guide in Missouri.
Florida
Florida is similarly abundant in chert rocks and varieties like Missouri. Here, you can find red fossiliferous chert in streams and creek beds at Cottondale.
All the quarries in Jackson County have chert, while you can also find the sedimentary rock along with flint specimens in stream banks, road cuts, and quarries around Washington County.
Chipley is another region with several limestone exposures, as well as road cuttings and other chert-rich habitats.
Gemmy chert may be found in a variety of areas around northern Florida. Marion, Alachua, and Sumter counties are well worth a visit.
These counties feature several limonite quarries, road cuttings, and exposures where gemmy chert specimens and fossilized ivory may be found.
In central Florida, chert may be found in quarries, road cuttings, and exposures near Bradford County. You may also look for limestone quarry seams around Crystal River.
The gulf beaches in Pinellas & Hillsborough Counties are also filled with chert specimens and are worth visiting.
TIP: Check out this article for a complete rockhounding guide in Florida.
Michigan
If you live or plan to visit Michigan, you should see the Keweenaw Peninsula to find some fantastic chert specimens. You can easily find chert and jasper at the Beeches north of Ahmeek.
At Keweenaw Point, you can find chert at the local beach gravels or search the beaches around McClain State Park. Some other essential beaches where you can easily find chert are near Lake Superior.
TIP: Check out this article for a complete rockhounding guide in Michigan.
California
California is another great state in which to find chert specimens. San Francisco, for example, has two great locations. You can visit Coyote Point and search for chert north of the yacht harbor or head to the outcrop only one mile northeast of Cliff House.
San Jose also has two great chert locations. The creeks northwest of Morgan Hill are abundant in chert specimens, but you can also try your luck at the area mines near New Almaden. In Kern County, you can find chert in the southeast foothills of Castle Butte.
TIP: Check out this article for a complete rockhounding guide in California.
New Mexico
New Mexico has various chert varieties, which you can find if you know where to look. In the northwestern parts of the state, you can find regular chert specimens in the northern area of Pedernal Park.
Gem-quality chert specimens may be discovered at La Madera, about one or two kilometers to the southeast. If you wish to locate chert and jasper specimens, visit Turquoise Hill and explore the surrounding region.
Chert is more often found in southwestern New Mexico than in other sections of the state. The western slopes of the Mimbres Mountains are rich in chert, but if you want to locate chert in various hues, go directly to Meerschaum and explore the area’s surfaces.
Regular chert specimens are also abundant in Deming, particularly in draws, washes, and surfaces. Derry has several exceptionally colorful chert specimens, particularly the draws and washes. If you’re looking for high-quality gem specimens, go to Elephant Butte. Search the western parts of the major road.
TIP: For a complete rockhounding guide in New Mexico, check out this article.
TIP: Holes in rocks are a sign of the next stage of the rock cycle. Find out how holes in stones are formed and how to drill them by yourself in the article below:
Holes in Rocks Explained: How Are Formed & What Causes Them
FAQ About Finding Chert Rocks
I still have not found the answer to your questions about finding chert. Find frequently asked questions in the section below:
Where Is Chert Most Likely Formed?
Chert rock specimens most likely form in carbonate environments or clastic-clean carbonate environments. Banded iron formations or alkaline lakes are typical environments where chert forms.
Are Chert and Flint the Same Thing?
Flint is a variety of chert that forms in chalk limestone deposits or marl, while chert often forms in layers or nodules in limestone deposits. They are very similar in hardness and appearance, yet flint is only one type of chert.
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Conclusion
Chert is one of the best-known sedimentary rocks, appearing in a variety of hues and shapes. It also comes in a variety of materials, including flint, mozarkite, bedded chert, jasper, onyx, and agate.
Follow the advice above and visit some of the states or locations suggested to discover this well-known yet rare rock. Happy chert hunting!
TIP: Rock collectors know how hard it is to find perfect specimens for tumbling. Some are lucky due to their local geology. Find out the best environments in the article below:
7 Best Places to Find Rocks for Tumbling in Nature