fossil

Fossilized Insect in Nodular Matrix

Invertebrata / Insecta fossil in sedimentary concretion

Hardness varies depending on the host rock (typically Mohs 3-5 for limestone/shale); Color ranges from earthy brown, tan, to grey with darker carbonized or mineralized fossil impressions; Luster is dull to earthy; Cryptocrystalline or fine-grained sedimentary structure.

Identified August 7, 2026More fossil →

Explore Fossilized Insect in Nodular Matrix in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed through rapid burial of organic remains in fine-grained sediments (such as mud or silt), followed by mineralization, permineralization, or carbonization over millions of years within sedimentary basins, often dating from the Paleozoic, Mesozoic, or Cenozoic eras.

Uses & applications

Scientific research, educational display, and paleontological collecting.

Geological facts

Fossilized insects are exceptionally rare compared to marine fossils because their delicate exoskeletons decompose quickly. Exceptional preservation often occurs in specific depositional environments like fine-grained lake beds or concretion nodules.

Field identification & locations

Look for distinct outlines, segmentation, or carbonized impressions embedded within split sedimentary rocks or concretions. Common in famous fossil-bearing formations globally, such as Mazon Creek in Illinois or various shales and limestones worldwide.

Other fossil specimens

See all

Crinoid Stem Fossil in Matrix

Phylum Echinodermata, Class Crinoidea

fossil

Chert with Fossil Brachiopod

Microcrystalline Quartz (SiO2) with Calcitic Brachiopod inclusion

sedimentary

Sedimentary Outcrop (Sandstone/Shale)

Sedimentary bedrock formation (variable composition)

sedimentary

Crinoid Stem Fossils (Indian Beads / St. Cuthbert's Beads)

Crinoid columnal ossicles (phylum Echinodermata)

fossil

Fossilized Crinoid Stem in Limestone

Crinoidea (Class) in Calcium Carbonate (CaCO3) matrix

fossil

Fossiliferous Limestone

Limestone with embedded fossil cross-section

sedimentary