Where is Concretion with possible mineral inclusion found?
Sedimentary concretion with unknown mineral
Got a photo? Identify rocks instantly with the Rockby app
Open the appConcretion with possible mineral inclusion occurs in specific geological environments. Knowing where to look, and in what kind of rock, is the difference between going home empty-handed and finding a great specimen.
Where to find Concretion with possible mineral inclusion
Ohio, USA
Famous for concretions, particularly in the Ohio Shale, often containing pyrite or marcasite inclusions.
Kansas, USA
Known for large, spherical concretions in Cretaceous shales, sometimes with fossil inclusions.
Utah, USA
Moqui Marbles (iron oxide concretions) are found in Navajo Sandstone, sometimes with internal structures.
New Zealand
Moeraki Boulders are large, spherical septarian concretions found on Koekohe Beach.
Worldwide
Concretions are globally distributed in sedimentary basins wherever suitable conditions for their formation exist.
Collecting tips
- Look for resistant masses. Concretions are often harder than the surrounding host rock and will weather out, appearing as distinct nodules or spheres on eroded surfaces, stream beds, or cliffs.
- Examine sedimentary outcrops. Search in shales, siltstones, and sandstones, particularly those with evidence of past organic activity or fossil content, as these often provide nuclei for concretion growth.
- Break open specimens carefully. To reveal potential internal structures or mineral inclusions, carefully break open promising concretions. Use appropriate safety gear (eye protection, gloves).
- Observe shape and symmetry. Many concretions are spherical, ovoid, or disc-shaped, which can help distinguish them from irregular rock fragments.
Quick Check
- Color:
- Variable (brown, grey, black, red, yellow)
- Luster:
- Dull to earthy (concretion exterior); variable for internal minerals (vitreous, metallic, pearly)
- Streak:
- Variable, depending on the dominant cementing mineral and any inclusions. For example, calcite (white), hematite (red-brown), pyrite (greenish-black).
Explore Concretion with possible mineral inclusion
Identify rocks anywhere
Free on iOS, Android, and Web. Photo identification, full database, and your personal collection.