Where is Chert Nodule with Fossil Mold found?
Chert (cryptocrystalline quartz) with internal mold of a fossil
Got a photo? Identify rocks instantly with the Rockby app
Open the appChert Nodule with Fossil Mold 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 Chert Nodule with Fossil Mold
Chalk Downs of England
Famous for flint nodules (a type of chert) containing abundant fossil molds, particularly of echinoids (sea urchins) and bivalves, within the Cretaceous Chalk Group.
Midwestern United States (e.g., Indiana, Kentucky, Ohio)
Paleozoic limestones often contain chert nodules with well-preserved molds of brachiopods, crinoids, and other marine invertebrates.
Florida, United States
Miocene and Pliocene limestones can yield chert nodules with molds of marine shells.
Various global marine sedimentary basins
Wherever silica-rich waters interacted with fossiliferous carbonate sediments, chert nodules with fossil molds can be found. This includes many ancient continental shelf and platform environments.
Collecting tips
- Look in Limestone Quarries and Outcrops. Chert nodules are commonly found weathering out of limestone and dolomite formations. Look for areas where these rocks are exposed.
- Examine Stream Beds and Gravel Pits. Erosion can free chert nodules from their host rock, and they often accumulate in stream beds or gravel deposits due to their hardness and resistance to weathering.
- Break Open Nodules. Fossil molds are often internal. Carefully breaking open chert nodules (with appropriate safety gear) can reveal the fossil within. Look for nodules with unusual shapes or bumps that might indicate an internal fossil.
- Identify Chert Characteristics. Learn to recognize the typical appearance of chert: hard, dense, cryptocrystalline, often with a waxy luster on fresh breaks, and conchoidal fracture. This will help distinguish it from other rocks.
Quick Check
- Color:
- Variable (white, gray, black, brown, tan, red)
- Luster:
- Dull to waxy
- Streak:
- White
Explore Chert Nodule with Fossil Mold
Identify rocks anywhere
Free on iOS, Android, and Web. Photo identification, full database, and your personal collection.