sedimentary
Fossil Shell in Sedimentary Matrix
Bivalvia (fossil) in Calcium Carbonate Matrix
Hardness: 3-3.5 (Calcite); Color: creamy white to grey; Luster: dull to pearly; Structure: biogenic shell structure with surrounding grain texture; Cleavage: none (conchoidal or irregular fracture)
- Hardness
- 3-3
- Color
- creamy white to grey
- Luster
- dull to pearly
Identified More sedimentary →
Explore Fossil Shell in Sedimentary Matrix in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3-3.5 (Calcite); Color: creamy white to grey; Luster: dull to pearly; Structure: biogenic shell structure with surrounding grain texture; Cleavage: none (conchoidal or irregular fracture)
Formation & geological history
Formed during the lithification of marine sediments where shellfish remains were buried and pressurized over millions of years, often in limestone or shale environments.
Uses & applications
Educational specimens, decorative fossil displays, and used by collectors to study paleoenvironments. Fossiliferous limestone is also common in construction.
Geological facts
Bivalve fossils can date back as far as the Cambrian period (over 500 million years ago) and help geologists determine the age and environment of rock layers.
Field identification & locations
Identify by the distinct symmetrical shell impressions or calcified remains embedded in softer rock; commonly found in riverbeds, cliffs, and quarries that were formerly ancient seabeds.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Cone-in-cone structure (Limestone)
Cone-in-cone structure (Secondary Sedimentary Structure)
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary