fossil

Fossiliferous Limestone with Fossil Fragment

Fossiliferous Limestone (CaCO3 with organic remains)

AI-generated identification · may be incorrect

Hardness: 3 on Mohs scale (matrix); Color: Tan, brownish-pink, grey, yellowish-brown; Luster: Dull, earthy; Texture: Porous, granular to bioclastic structure

Hardness: 3 on Mohs scale (matrix)
Color: Tan, brownish-pink, grey, yellowish-brown
Luster: Dull, earthy

Identified July 26, 2026More fossil →

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Physical properties

Hardness: 3 on Mohs scale (matrix); Color: Tan, brownish-pink, grey, yellowish-brown; Luster: Dull, earthy; Texture: Porous, granular to bioclastic structure

Formation & geological history

Formed in warm, shallow marine or freshwater environments by the accumulation and cementation of organic remains such as shell fragments, coral, or crinoids alongside calcium carbonate sediment over millions of years.

Uses & applications

Used primarily for fossil collecting, educational study, local building material, and crushed stone aggregate.

Geological facts

Fossiliferous limestones often preserve snapshot ecosystems from periods like the Paleozoic or Mesozoic eras. The small pitted or porous structures seen in the lower matrix represent shell molds or dissolved organic matter.

Field identification & locations

Identified by its effervescence (fizzing) when exposed to dilute hydrochloric acid, earthy texture, soft matrix compared to quartz, and visible inclusions of fossilized shell or skeletal fragments. Widely found in sedimentary rock formations around former sea beds.