fossil

Fossilized Dinosaur Bone

Perineralized Bone (Fluorapatite/Quartz replacement)

Hardness typically 5.5 to 7 on the Mohs scale due to mineral replacement (silicification), varying colors including brown, red, grey, and black, dull to vitreous luster on polished surfaces, amorphous internal trabecular structure preserved in stone.

Identified July 30, 2026More fossil →

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Physical properties

Formation & geological history

Formed through perimineralization or petrifaction, where groundwater rich in minerals like silica or calcite replaces the original organic components of buried bone over millions of years (often Mesozoic era, Cretaceous or Jurassic periods).

Uses & applications

Used primarily as paleontological specimens, educational exhibits, lapidary art, and collector display pieces.

Geological facts

Fossil bone often retains the microscopic cellular structure (trabeculae) of the living animal, visible under magnification even after complete stone replacement.

Field identification & locations

Identified by distinct porous cellular or spongy bone texture on broken surfaces and heavy weight compared to modern bone; commonly found in sedimentary rock formations worldwide, such as the Morrison Formation in the US.

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Sedimentary bedrock formation (variable composition)

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Chert with Fossil Brachiopod

Microcrystalline Quartz (SiO2) with Calcitic Brachiopod inclusion

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Fossilized Crinoid Stem in Limestone

Crinoidea (Class) in Calcium Carbonate (CaCO3) matrix

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Fossiliferous Limestone

Limestone with embedded fossil cross-section

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Fossiliferous Limestone with Crinoid stems

Limestone (CaCO3) containing Crinoidea fossils

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